get_thread

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

No annotations are provided, so the description carries the full burden. It states that messages are parsed but does not disclose behavior regarding read scopes, error handling (e.g., missing thread), rate limits, or the structure of the returned data beyond 'readable headers + body text/html'.

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 a single, front-loaded sentence that efficiently states the verb and resource. It could be slightly improved by adding a second sentence about usage without being verbose.

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?

With no output schema and minimal annotations, the description is incomplete. It does not specify the exact return structure (e.g., a thread object containing messages), pagination, or field details. For a fetch tool with three parameters, more context is needed.

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 33% (only account gets a description). The description does not explain thread_id or format beyond what the schema provides (e.g., enum values). It adds no new meaning to parameters.

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 tool fetches a Gmail thread by ID and parses messages into readable headers and body. It uses a specific verb ('Fetch') and resource ('Gmail thread'), distinguishing it from siblings like search_threads or label_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?

No guidance is provided on when to use this tool versus alternatives such as search_threads or get_attachment. The description does not mention prerequisites, context, or exclusions.

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