mail_get_thread

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

Descriptions adds useful context beyond the annotations: it returns full bodies, orders oldest first, and requires Mail.Read. However, the claim 'every message' is not strictly accurate since the max_results parameter can limit the number returned; this is a minor inconsistency that prevents a 5.

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 two sentences, front-loaded with the core action, and every clause earns its place. No fluff or repetition of schema details.

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 read-only tool with two well-documented parameters and strong annotations, the description covers purpose, usage, ordering, and auth. It doesn't explain return format in detail, but no output schema exists and the statement about full message bodies is likely sufficient. The max_results caveat is the only notable omission.

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 coverage is 100% with clear descriptions for both parameters. The tool description does not add meaning beyond the schema except for the hint that conversation_id comes from listing tools, which is minor. Baseline of 3 is appropriate.

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 reads every message in one email conversation, oldest first, and distinguishes itself from mail listing tools by returning full message bodies rather than previews. The verb 'read' and resource 'email conversation' are specific and unambiguous.

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?

It explicitly says to use this tool when you have a conversation ID from any mail listing tool and need full bodies before replying or summarising. It does not explicitly name alternative tools or state when not to use it, but the context is clear enough for an agent to select it appropriately.

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