fix: remove avoidable model runtime limits

Preserve long histories and parsed attachments, expose paged process and Subagent output, isolate MCP discovery failures, and expand browser snapshots and knowledge result selection. Remove fixed Harness output and updated remote Runtime duration limits.

Keep released Agent profile and v1 bridge compatibility while enabling larger framed exchanges and optional limits for updated peers. Document remote coverage requirements and real-model boundary validation.

Release note: Long model tasks can retain more context and continue reading complete tool output; remote execution preserves compatibility with released Agents. Updated remote limits require an updated Agent and Runtime bundle.

src/main/agent/model-tool-provider.ts

@@ -50,6 +50,10 @@ import type { BrowserTabId } from '../../shared/contracts'
 import { searchWorkspaceWithRipgrep } from './direct-model-ripgrep'
 import { applyWorkspacePatch } from './workspace-apply-patch'
 import { readWorkspaceLines } from './workspace-read-lines'
+import {
+  PAGED_OUTPUT_DEFAULT_PAGE_BYTES,
+  PAGED_OUTPUT_MAX_PAGE_BYTES
+} from './paged-output-store'
 
 const MAX_MODEL_TOOLS = 100
 const MAX_TOOL_RESULT_BYTES = 256 * 1024
@@ -94,6 +98,9 @@ const processExecuteTool = builtinModelTools.find(
 const subagentDelegateTool = builtinModelTools.find(
   (tool) => tool.name === 'subagent_delegate'
 )!
+const outputReadTool = builtinModelTools.find(
+  (tool) => tool.name === 'output_read'
+)!
 const magicNoteWriteToolNameSet = new Set<string>(
   magicNoteWriteToolNames
 )
@@ -168,6 +175,19 @@ const applyPatchInputSchema = z
   })
   .strict()
 
+const outputReadInputSchema = z
+  .object({
+    handle: z.string().min(1)
+      .describe('The handle returned in an output reference.'),
+    cursor: z.number().int().min(0).default(0)
+      .describe('UTF-8 byte offset. Use the returned nextCursor to continue, or 0 to reread.'),
+    limitBytes: z.number().int().min(1)
+      .max(PAGED_OUTPUT_MAX_PAGE_BYTES)
+      .default(PAGED_OUTPUT_DEFAULT_PAGE_BYTES)
+      .describe('Maximum page bytes; a tiny limit may expand to fit one complete UTF-8 character.')
+  })
+  .strict()
+
 const webSearchInputSchema = z
   .object({
     query: z.string().trim().min(1).max(1_000),
@@ -451,7 +471,8 @@ function toModelToolJsonSchema(
   schema: z.ZodType
 ): Record<string, unknown> {
   const value = z.toJSONSchema(schema, {
-    target: 'draft-7'
+    target: 'draft-7',
+    io: 'input'
   }) as Record<string, unknown>
   Reflect.deleteProperty(value, '$schema')
   return value
@@ -731,6 +752,8 @@ export class ModelToolProvider implements ModelToolProviderLike {
       (this.webSearchEnabled ? 2 : 0) +
       (this.programming.processService ? 1 : 0) +
       (this.programming.subagentService ? 1 : 0) +
+      (this.programming.processService || this.programming.subagentService
+        ? 1 : 0) +
       (this.knowledgeGateway ? maximumScopedToolCount : 0)
     )
   }
@@ -929,7 +952,9 @@ export class ModelToolProvider implements ModelToolProviderLike {
         displayName: processExecuteTool.displayName,
         description:
           `Run one foreground command in the current workspace with current-user permissions using ${capability.shell.label}. ` +
-          'Returns bounded stdout, stderr, exit status, duration, and truncation state. Non-zero exit codes are command results.',
+          'Returns stdout/stderr prefix previews, exit status, duration, and truncation state. ' +
+          'Full output is retained until conversation release. When stdoutReference or stderrReference is present, ' +
+          'call output_read with its handle and nextCursor to continue; follow page nextCursor until eof. Non-zero exit codes are command results.',
         inputSchema: toModelToolJsonSchema(
           processExecuteInputSchema
         ),
@@ -955,7 +980,9 @@ export class ModelToolProvider implements ModelToolProviderLike {
         displayName: subagentDelegateTool.displayName,
         description:
           'Delegate one focused task to a temporary direct-model Subagent. ' +
-          'The child inherits the current model, workspace, work mode, and enabled tools, cannot delegate again, and returns bounded output to the parent.',
+          'The child inherits the current model, workspace, work mode, and enabled tools, cannot delegate again, and returns an output prefix preview to the parent. ' +
+          'When outputReference is present, call output_read with its handle and nextCursor to read the rest, including partial output from failed or cancelled runs. ' +
+          'Full output remains available until the parent conversation is released.',
         inputSchema: toModelToolJsonSchema(
           directModelSubagentInputSchema
         ),
@@ -964,6 +991,30 @@ export class ModelToolProvider implements ModelToolProviderLike {
     ]
   }
 
+  private getOutputReadTool(
+    context: ModelToolCallContext
+  ): ModelToolDefinition[] {
+    if (
+      context.runtimeTarget !== 'model' ||
+      (!this.programming.processService && !this.programming.subagentService)
+    ) {
+      return []
+    }
+    return [
+      {
+        name: outputReadTool.name,
+        displayName: outputReadTool.displayName,
+        description:
+          'Read retained process or Subagent output from this conversation. ' +
+          'Use the reference handle and nextCursor to continue a preview, or cursor 0 to reread. ' +
+          'Follow each page nextCursor until eof; cursors are UTF-8 byte offsets. ' +
+          'Read-only in Ask and Execute. Handles expire when the conversation or runtime is released.',
+        inputSchema: toModelToolJsonSchema(outputReadInputSchema),
+        source: 'builtin'
+      }
+    ]
+  }
+
   private async connectMcpServer(
     server: ResolvedMcpServer,
     signal: AbortSignal,
@@ -1230,6 +1281,7 @@ export class ModelToolProvider implements ModelToolProviderLike {
       ? this.getWebSearchDefinitions()
       : []
     const subagentTools = this.getSubagentTool(context)
+    const outputTools = this.getOutputReadTool(context)
     const workspaceTools = await this.getWorkspaceTools(signal)
     if (context.workMode !== 'execute') {
       return [
@@ -1238,6 +1290,7 @@ export class ModelToolProvider implements ModelToolProviderLike {
         ),
         ...webTools,
         ...subagentTools,
+        ...outputTools,
         ...scopedTools
       ]
     }
@@ -1248,6 +1301,7 @@ export class ModelToolProvider implements ModelToolProviderLike {
       ...workspaceTools,
       ...processTools,
       ...subagentTools,
+      ...outputTools,
       ...(browserTools?.listTools() ?? []),
       ...webTools,
       ...[...bindings.values()].map((binding) => binding.definition),
@@ -1322,6 +1376,16 @@ export class ModelToolProvider implements ModelToolProviderLike {
         allowPermanent: false
       }
     }
+    if (tool.name === 'output_read') {
+      return {
+        scopeKey: 'model:builtin:output_read',
+        title: '允许续读工具输出？',
+        description: '读取当前会话已保留的进程或 Subagent 输出，不运行新命令。',
+        toolName: tool.displayName,
+        argumentSummary,
+        allowPermanent: false
+      }
+    }
     if (tool.name === 'subagent_delegate') {
       return {
         scopeKey: 'model:builtin:subagent_delegate',
@@ -1673,6 +1737,24 @@ export class ModelToolProvider implements ModelToolProviderLike {
         await applyWorkspacePatch(input.patch, this.workspaceAccess, signal)
       )
     }
+    if (name === 'output_read') {
+      if (context.runtimeTarget !== 'model') {
+        throw new Error('当前请求不允许续读工具输出')
+      }
+      const input = outputReadInputSchema.parse(argumentsValue)
+      const service = input.handle.startsWith('process:')
+        ? this.programming.processService
+        : input.handle.startsWith('subagent:')
+          ? this.programming.subagentService
+          : undefined
+      if (!service) {
+        throw new Error('分页输出句柄无效或服务不可用')
+      }
+      const page = await service.readOutput(
+        context.conversationId, input.handle, input.cursor, input.limitBytes
+      )
+      return createTextToolResult(boundedJson(page, '分页输出无法序列化'))
+    }
     if (name === 'process_execute') {
       if (
         context.runtimeTarget !== 'model' ||