pin_thread

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

With no annotations, the description carries full burden. It discloses the primary behavioral effect (pinning keeps thread at top) but lacks details on permissions, reversibility (unpin), or behavior if already pinned. This is a basic transparency level.

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 concise, front-loaded with the main action and purpose, followed by a use case and argument explanation. No unnecessary words or repetition.

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?

For a simple tool with one parameter and an output schema, the description covers the core aspects: what, when, and parameter source. It could mention that it's reversible via unpin_thread, but that is not essential given the simplicity and sibling list.

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?

The description explains 'thread_id' as 'The global thread ID' and suggests sources ('from list_threads or search_threads'), adding meaning beyond the schema's type and title. This directly helps the agent correctly supply the parameter.

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 clearly states the verb 'Pin' and the resource 'a thread', and explains the effect ('stays at the top of the course feed'). This distinguishes it from sibling tools like delete_thread or lock_thread, which have different purposes.

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?

The description provides clear context by stating it's 'Good for important announcements or FAQs', implying when to use it. It does not explicitly mention when not to use it or alternatives, but the context is sufficient for most agents.

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