fix(tools): reassemble fragmented tool names

src/Tool.test.ts

@@ -1,6 +1,7 @@
 import { describe, expect, test } from 'bun:test'
 
 import { findToolByNameOrUniquePrefix, type Tools } from './Tool.js'
+import { getAllBaseTools } from './tools.js'
 
 const tools = [
   { name: 'Read' },
@@ -37,4 +38,16 @@ describe('findToolByNameOrUniquePrefix', () => {
       ),
     ).toBeUndefined()
   })
+
+  test('recovers a missing final character for every registered built-in tool', () => {
+    const baseTools = getAllBaseTools()
+
+    for (const tool of baseTools) {
+      if (tool.name.length < 4 || tool.name.startsWith('mcp__')) continue
+      const truncatedName = tool.name.slice(0, -1)
+      expect(
+        findToolByNameOrUniquePrefix(baseTools, truncatedName)?.name,
+      ).toBe(tool.name)
+    }
+  })
 })

src/Tool.ts

@@ -374,6 +374,33 @@ export function findToolByName(tools: Tools, name: string): Tool | undefined {
   return tools.find(t => toolMatchesName(t, name))
 }
 
+/**
+ * Resolves a canonical tool name from an exact match or an unambiguous
+ * provider-truncated prefix. This string-only form is shared by API adapters,
+ * which have the advertised tool schemas but not the runtime Tool objects.
+ */
+export function resolveToolNameByUniquePrefix(
+  toolNames: readonly string[],
+  name: string,
+): string | undefined {
+  const uniqueToolNames = [...new Set(toolNames)]
+  if (uniqueToolNames.includes(name)) return name
+
+  if (name.length < 3 || name.startsWith('mcp__')) return undefined
+
+  const prefixMatches = uniqueToolNames.filter(toolName =>
+    toolName.startsWith(name),
+  )
+  const oneCharacterCompletions = prefixMatches.filter(
+    toolName => toolName.length === name.length + 1,
+  )
+  if (oneCharacterCompletions.length === 1) {
+    return oneCharacterCompletions[0]
+  }
+
+  return prefixMatches.length === 1 ? prefixMatches[0] : undefined
+}
+
 /**
  * Resolves a provider-truncated built-in tool name only when the prefix is
  * unambiguous. Prefer a unique one-character completion before considering
@@ -388,17 +415,13 @@ export function findToolByNameOrUniquePrefix(
   const exactMatch = findToolByName(tools, name)
   if (exactMatch) return exactMatch
 
-  if (name.length < 3 || name.startsWith('mcp__')) return undefined
-
-  const prefixMatches = tools.filter(tool => tool.name.startsWith(name))
-  const oneCharacterCompletions = prefixMatches.filter(
-    tool => tool.name.length === name.length + 1,
+  const resolvedName = resolveToolNameByUniquePrefix(
+    tools.map(tool => tool.name),
+    name,
   )
-  if (oneCharacterCompletions.length === 1) {
-    return oneCharacterCompletions[0]
-  }
-
-  return prefixMatches.length === 1 ? prefixMatches[0] : undefined
+  return resolvedName
+    ? tools.find(tool => tool.name === resolvedName)
+    : undefined
 }
 
 export type Tool<

src/components/Messages.tsx

@@ -16,7 +16,7 @@ import { Box, Text } from '../ink.js';
 import { useShortcutDisplay } from '../keybindings/useShortcutDisplay.js';
 import type { Screen } from '../screens/REPL.js';
 import type { Tools } from '../Tool.js';
-import { findToolByName } from '../Tool.js';
+import { findToolByNameOrUniquePrefix } from '../Tool.js';
 import type { AgentDefinitionsResult } from '../tools/AgentTool/loadAgentsDir.js';
 import type { Message as MessageType, NormalizedMessage, ProgressMessage as ProgressMessageType, RenderableMessage } from '../types/message.js';
 import { type AdvisorBlock, isAdvisorBlock } from '../utils/advisor.js';
@@ -589,7 +589,7 @@ const MessagesImpl = ({
     const b_0 = msg_6.message.content[0];
     if (b_0?.type !== 'tool_result' || b_0.is_error || !msg_6.toolUseResult) return false;
     const name = lookupsRef.current.toolUseByToolUseID.get(b_0.tool_use_id)?.name;
-    const tool = name ? findToolByName(tools, name) : undefined;
+    const tool = name ? findToolByNameOrUniquePrefix(tools, name) : undefined;
     return tool?.isResultTruncated?.(msg_6.toolUseResult as never) ?? false;
   }, [tools]);
   const canAnimate = (!toolJSX || !!toolJSX.shouldContinueAnimation) && !toolUseConfirmQueue.length && !isMessageSelectorVisible;
@@ -658,7 +658,7 @@ const MessagesImpl = ({
       const tr = msg_9.message.content.find(b_1 => b_1.type === 'tool_result');
       if (tr && 'tool_use_id' in tr) {
         const tu = lookups_0.toolUseByToolUseID.get(tr.tool_use_id);
-        const tool_0 = tu && findToolByName(tools, tu.name);
+        const tool_0 = tu && findToolByNameOrUniquePrefix(tools, tu.name);
         const extracted = tool_0?.extractSearchText?.(msg_9.toolUseResult as never);
         // undefined = tool didn't implement → keep heuristic. Empty
         // string = tool says "nothing to index" → respect that.

src/components/messages/AssistantToolUseMessage.tsx

@@ -8,7 +8,7 @@ import { BLACK_CIRCLE } from '../../constants/figures.js';
 import { stringWidth } from '../../ink/stringWidth.js';
 import { Box, Text, useTheme } from '../../ink.js';
 import { useAppStateMaybeOutsideOfProvider } from '../../state/AppState.js';
-import { findToolByName, type Tool, type ToolProgressData, type Tools } from '../../Tool.js';
+import { findToolByNameOrUniquePrefix, type Tool, type ToolProgressData, type Tools } from '../../Tool.js';
 import type { ProgressMessage } from '../../types/message.js';
 import { useIsClassifierChecking } from '../../utils/classifierApprovalsHook.js';
 import { logError } from '../../utils/log.js';
@@ -64,7 +64,7 @@ export function AssistantToolUseMessage(t0) {
         t1 = null;
         break bb0;
       }
-      const tool = findToolByName(tools, param.name);
+      const tool = findToolByNameOrUniquePrefix(tools, param.name);
       if (!tool) {
         t1 = null;
         break bb0;

src/components/messages/CollapsedReadSearchContent.tsx

@@ -4,7 +4,7 @@ import { basename } from 'path';
 import React, { useRef } from 'react';
 import { useMinDisplayTime } from '../../hooks/useMinDisplayTime.js';
 import { Ansi, Box, Text, useTheme } from '../../ink.js';
-import { findToolByName, type Tools } from '../../Tool.js';
+import { findToolByNameOrUniquePrefix, type Tools } from '../../Tool.js';
 import { getReplPrimitiveTools } from '../../tools/REPLTool/primitiveTools.js';
 import type { CollapsedReadSearchGroup, NormalizedAssistantMessage } from '../../types/message.js';
 import { uniq } from '../../utils/array.js';
@@ -55,7 +55,7 @@ function VerboseToolUse(t0) {
   if ($[0] !== bg || $[1] !== content.id || $[2] !== content.input || $[3] !== content.name || $[4] !== inProgressToolUseIDs || $[5] !== lookups || $[6] !== shouldAnimate || $[7] !== theme || $[8] !== tools) {
     t2 = Symbol.for("react.early_return_sentinel");
     bb0: {
-      const tool = findToolByName(tools, content.name) ?? findToolByName(getReplPrimitiveTools(), content.name);
+      const tool = findToolByNameOrUniquePrefix(tools, content.name) ?? findToolByNameOrUniquePrefix(getReplPrimitiveTools(), content.name);
       if (!tool) {
         t2 = null;
         break bb0;

src/components/messages/GroupedToolUseContent.tsx

@@ -1,6 +1,6 @@
 import type { ToolResultBlockParam, ToolUseBlockParam } from '@anthropic-ai/sdk/resources/messages/messages.mjs';
 import * as React from 'react';
-import { filterToolProgressMessages, findToolByName, type Tools } from '../../Tool.js';
+import { filterToolProgressMessages, findToolByNameOrUniquePrefix, type Tools } from '../../Tool.js';
 import type { GroupedToolUseMessage } from '../../types/message.js';
 import type { buildMessageLookups } from '../../utils/messages.js';
 type Props = {
@@ -17,7 +17,7 @@ export function GroupedToolUseContent({
   inProgressToolUseIDs,
   shouldAnimate
 }: Props): React.ReactNode {
-  const tool = findToolByName(tools, message.toolName);
+  const tool = findToolByNameOrUniquePrefix(tools, message.toolName);
   if (!tool?.renderGroupedToolUse) {
     return null;
   }

src/components/messages/UserToolResultMessage/utils.tsx

@@ -1,7 +1,7 @@
 import { c as _c } from "react-compiler-runtime";
 import type { ToolUseBlockParam } from '@anthropic-ai/sdk/resources/index.mjs';
 import { useMemo } from 'react';
-import { findToolByName, type Tool, type Tools } from '../../../Tool.js';
+import { findToolByNameOrUniquePrefix, type Tool, type Tools } from '../../../Tool.js';
 import type { buildMessageLookups } from '../../../utils/messages.js';
 export function useGetToolFromMessages(toolUseID, tools, lookups) {
   const $ = _c(7);
@@ -13,7 +13,7 @@ export function useGetToolFromMessages(toolUseID, tools, lookups) {
         t0 = null;
         break bb0;
       }
-      const tool = findToolByName(tools, toolUse.name);
+      const tool = findToolByNameOrUniquePrefix(tools, toolUse.name);
       if (!tool) {
         t0 = null;
         break bb0;

src/components/tasks/renderToolActivity.tsx

@@ -1,11 +1,11 @@
 import React from 'react';
 import { Text } from '../../ink.js';
 import type { Tools } from '../../Tool.js';
-import { findToolByName } from '../../Tool.js';
+import { findToolByNameOrUniquePrefix } from '../../Tool.js';
 import type { ToolActivity } from '../../tasks/LocalAgentTask/LocalAgentTask.js';
 import type { ThemeName } from '../../utils/theme.js';
 export function renderToolActivity(activity: ToolActivity, tools: Tools, theme: ThemeName): React.ReactNode {
-  const tool = findToolByName(tools, activity.toolName);
+  const tool = findToolByNameOrUniquePrefix(tools, activity.toolName);
   if (!tool) {
     return activity.toolName;
   }

src/hooks/useDirectConnect.ts

@@ -14,7 +14,7 @@ import {
   DirectConnectSessionManager,
 } from '../server/directConnectManager.js'
 import type { Tool } from '../Tool.js'
-import { findToolByName } from '../Tool.js'
+import { findToolByNameOrUniquePrefix } from '../Tool.js'
 import type { Message as MessageType } from '../types/message.js'
 import type { PermissionAskDecision } from '../types/permissions.js'
 import { logForDebugging } from '../utils/debug.js'
@@ -90,7 +90,7 @@ export function useDirectConnect({
         )
 
         const tool =
-          findToolByName(toolsRef.current, request.tool_name) ??
+          findToolByNameOrUniquePrefix(toolsRef.current, request.tool_name) ??
           createToolStub(request.tool_name)
 
         const syntheticMessage = createSyntheticAssistantMessage(

src/hooks/useInboxPoller.ts

@@ -11,7 +11,7 @@ import {
   useAppStateStore,
   useSetAppState,
 } from '../state/AppState.js'
-import { findToolByName } from '../Tool.js'
+import { findToolByNameOrUniquePrefix } from '../Tool.js'
 import { isInProcessTeammateTask } from '../tasks/InProcessTeammateTask/types.js'
 import { getAllBaseTools } from '../tools.js'
 import type { PermissionUpdate } from '../types/permissions.js'
@@ -267,7 +267,10 @@ export function useInboxPoller({
           // Route through the standard ToolUseConfirmQueue so tmux workers
           // get the same tool-specific UI (BashPermissionRequest, FileEditToolDiff, etc.)
           // as in-process teammates.
-          const tool = findToolByName(getAllBaseTools(), parsed.tool_name)
+          const tool = findToolByNameOrUniquePrefix(
+            getAllBaseTools(),
+            parsed.tool_name,
+          )
           if (!tool) {
             logForDebugging(
               `[InboxPoller] Unknown tool ${parsed.tool_name}, skipping permission request`,

src/hooks/useRemoteSession.ts

@@ -18,7 +18,7 @@ import {
 import { useSetAppState } from '../state/AppState.js'
 import type { AppState } from '../state/AppStateStore.js'
 import type { Tool } from '../Tool.js'
-import { findToolByName } from '../Tool.js'
+import { findToolByNameOrUniquePrefix } from '../Tool.js'
 import type { Message as MessageType } from '../types/message.js'
 import type { PermissionAskDecision } from '../types/permissions.js'
 import { logForDebugging } from '../utils/debug.js'
@@ -338,7 +338,7 @@ export function useRemoteSession({
 
         // Look up the Tool object by name, or create a stub for unknown tools
         const tool =
-          findToolByName(toolsRef.current, request.tool_name) ??
+          findToolByNameOrUniquePrefix(toolsRef.current, request.tool_name) ??
           createToolStub(request.tool_name)
 
         const syntheticMessage = createSyntheticAssistantMessage(

src/hooks/useSSHSession.ts

@@ -23,7 +23,7 @@ import {
 import type { SSHSession } from '../ssh/createSSHSession.js'
 import type { SSHSessionManager } from '../ssh/SSHSessionManager.js'
 import type { Tool } from '../Tool.js'
-import { findToolByName } from '../Tool.js'
+import { findToolByNameOrUniquePrefix } from '../Tool.js'
 import type { Message as MessageType } from '../types/message.js'
 import type { PermissionAskDecision } from '../types/permissions.js'
 import { logForDebugging } from '../utils/debug.js'
@@ -94,7 +94,7 @@ export function useSSHSession({
         )
 
         const tool =
-          findToolByName(toolsRef.current, request.tool_name) ??
+          findToolByNameOrUniquePrefix(toolsRef.current, request.tool_name) ??
           createToolStub(request.tool_name)
 
         const syntheticMessage = createSyntheticAssistantMessage(

src/query.ts

@@ -25,7 +25,7 @@ import {
 } from 'src/services/analytics/index.js'
 import { ImageSizeError } from './utils/imageValidation.js'
 import { ImageResizeError } from './utils/imageResizer.js'
-import { findToolByName, type ToolUseContext } from './Tool.js'
+import { findToolByNameOrUniquePrefix, type ToolUseContext } from './Tool.js'
 import { asSystemPrompt, type SystemPrompt } from './utils/systemPromptType.js'
 import type {
   AssistantMessage,
@@ -947,7 +947,7 @@ async function* queryLoop(
                   typeof block.input === 'object' &&
                   block.input !== null
                 ) {
-                  const tool = findToolByName(
+                  const tool = findToolByNameOrUniquePrefix(
                     toolUseContext.options.tools,
                     block.name,
                   )