refactor(delegate-task): split tools.ts to comply with 200 LOC module rule

Extract the tool description/category metadata into tool-description.ts and move argument normalization plus validation into tool-argument-preparation.ts. This keeps createDelegateTask focused on orchestration while preserving behavior and bringing tools.ts under the module LOC rule.

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

src/tools/delegate-task/tool-description.ts

@@ -0,0 +1,88 @@
+import type { AvailableCategory, AvailableSkill } from "../../agents/dynamic-agent-prompt-builder"
+import { mergeCategories } from "../../shared/merge-categories"
+import { CATEGORY_DESCRIPTIONS } from "./constants"
+import type { DelegateTaskToolOptions } from "./types"
+
+export interface DelegateTaskPresentation {
+  availableCategories: AvailableCategory[]
+  availableSkills: AvailableSkill[]
+  categoryExamples: string
+  description: string
+}
+
+export function createDelegateTaskPresentation(options: DelegateTaskToolOptions): DelegateTaskPresentation {
+  const { userCategories } = options
+  const allCategories = mergeCategories(userCategories)
+  const categoryNames = Object.keys(allCategories)
+  const categoryExamples = categoryNames.join(", ")
+
+  const availableCategories: AvailableCategory[] = options.availableCategories
+    ?? Object.entries(allCategories).map(([name, categoryConfig]) => {
+      const userDescription = userCategories?.[name]?.description
+      const builtinDescription = CATEGORY_DESCRIPTIONS[name]
+      const description = userDescription || builtinDescription || "General tasks"
+
+      return {
+        name,
+        description,
+        model: categoryConfig.model,
+      }
+    })
+
+  const availableSkills: AvailableSkill[] = options.availableSkills ?? []
+
+  const categoryList = categoryNames.map(name => {
+    const userDescription = userCategories?.[name]?.description
+    const builtinDescription = CATEGORY_DESCRIPTIONS[name]
+    const description = userDescription || builtinDescription
+    return description ? `  - ${name}: ${description}` : `  - ${name}`
+  }).join("\n")
+
+  const description = `Spawn agent task with category-based or direct agent selection.
+  
+  ⚠️  CRITICAL: You MUST provide EITHER category OR subagent_type. Omitting BOTH will FAIL.
+  
+  **COMMON MISTAKE (DO NOT DO THIS):**
+  \`\`\`
+  task(description="...", prompt="...", run_in_background=false)  // ❌ FAILS - missing category AND subagent_type
+  \`\`\`
+  
+  **CORRECT - Using category:**
+  \`\`\`
+  task(category="quick", load_skills=[], description="Fix type error", prompt="...", run_in_background=false)
+  \`\`\`
+  
+  **CORRECT - Using subagent_type:**
+  \`\`\`
+  task(subagent_type="explore", load_skills=[], description="Find patterns", prompt="...", run_in_background=true)
+  \`\`\`
+  
+  REQUIRED: Provide ONE of:
+  - category: For task delegation (uses Sisyphus-Junior with category-optimized model)
+  - subagent_type: For direct agent invocation (explore, librarian, oracle, etc.)
+  
+  **DO NOT provide both.** If category is provided, subagent_type is ignored.
+  
+  - load_skills: ALWAYS REQUIRED. Pass [] if no skills needed, or ["skill-1", "skill-2"] for category tasks.
+  - category: Use predefined category → Spawns Sisyphus-Junior with category config
+    Available categories:
+  ${categoryList}
+  - subagent_type: Use specific agent directly (explore, librarian, oracle, metis, momus)
+  - run_in_background: REQUIRED. true=async (returns task_id), false=sync (waits). Use background=true ONLY for parallel exploration with 5+ independent queries.
+  - task_id: Existing task to continue (from previous task output). Continues the same subagent session with FULL CONTEXT PRESERVED.
+  - command: The command that triggered this task (optional, for slash command tracking).
+  
+  **WHEN TO USE task_id:**
+  - Task failed/incomplete → task_id with "fix: [specific issue]"
+  - Need follow-up on previous result → task_id with additional question
+  - Multi-turn conversation with same agent → always task_id instead of new task
+  
+  Prompts MUST be in English.`
+
+  return {
+    availableCategories,
+    availableSkills,
+    categoryExamples,
+    description,
+  }
+}