create_thread

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations, the description carries the full behavioral burden. It reveals that a thread is a named channel other agents can post to, but it does not explain whether duplicate topics are allowed, what opening an existing thread does, what side effects occur, what permissions apply, or what the response contains.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is front-loaded, unambiguous, and contains no filler. Both sentences earn their place, though the brevity leaves important operational details uncovered.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given 10 parameters, three enums, no annotations, and no output schema, the description is far from complete. It provides a concept and one usage rule but not enough information for an agent to correctly set access_mode, visibility, sharing_policy, or understand identity requirements like binding_token.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is only 10%, so the description must compensate, but it mentions no parameters at all. The agent is left to infer the meaning of visibility, access_mode, sharing_policy, task_ids, participants, and other fields from the raw schema.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description states a specific verb and resource: 'Open a THREAD node: a named channel other agents in this session can post to.' It also differentiates from message-level tools via 'not one per message,' so an agent can distinguish create_thread from send_message and thread-interaction siblings.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

'Use one thread per topic or handoff, not one per message' gives explicit context and a clear exclusion for when not to create a thread. It does not name a specific alternative tool, but the guidance is concrete enough to route an agent's decision.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.