First attempts to create tasks via MCP fails

[asavkinRendMate]

When agent try to use MCP function tasks_create first time, it falls down with errors like "Sibling tool call errored" or "Error: MCP Error -32602: Input validation error: Invalid arguments for tool tasks_create:". Then agent repeat attempt with other params and task go through,

[prih]

Root cause: insufficient schema descriptions, not a server bug

After thorough investigation (schema validation, session lifecycle, transport layer, Zod v4/v4-mini compatibility, race conditions) — the server-side code is correct. Validation works properly on every call, including the first one.

What actually happens

1. The LLM client sends tasks_create with invalid arguments on the first attempt — typically a wrong enum value like "normal" instead of "medium" for priority, or "open" instead of "backlog" for status. The enum values were not listed in field descriptions, so the LLM had to guess.

2. The server correctly rejects with -32602 Input validation error.

3. "Sibling tool call errored" is a client-side cascade — when the LLM calls multiple tools in parallel and one fails, the others are marked as sibling errors.

4. On retry, the LLM adjusts parameters based on the error message and succeeds.

Fix

Improved .describe() text across all 29 MCP tool files to explicitly list allowed enum values and defaults:

• priority → 'Priority: "critical", "high", "medium", or "low"'
• status → '"backlog", "todo", "in_progress", "review", "done", or "cancelled"'
• targetGraph, kind, source, searchMode — same treatment
• Numeric fields now include default values and examples (e.g. dueDate → "Unix timestamp in ms, e.g. 1735689600000")

This should eliminate most first-call failures since LLM clients will see the exact allowed values in the tool schema descriptions.