close_thread

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

With no annotations, the description carries the burden and does disclose an important authorization requirement and a mutating state change. It does not reveal side effects on subscribers or messages, reversibility, or failure behavior, leaving transparency partial.

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?

A single front-loaded sentence with no filler. The core action and the key authorization constraint appear immediately.

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 mutation with no annotations or output schema, it covers purpose and authorization but omits postconditions, return/error behavior, and interactions with related thread tools. It is minimally viable but not complete.

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?

binding_token is already well documented in the schema, and thread_id is evident from the word 'thread'. The description adds no parameter-specific format or context details, but the required parameter remains understandable.

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?

Directly states the action ('Close') and the resource ('a thread'), and adds the authorization scope. This clearly distinguishes it from lifecycle siblings like create_thread, poll_thread, and ack_thread.

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 authority constraint ('under opener or campaign-coordinator authority') gives useful context for who may call it, and the verb implies the lifecycle moment. However, it does not explicitly name alternatives or state when not to use it, so usage must be inferred.

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