search_emails

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

Annotations already declare readOnlyHint=true and destructiveHint=false, covering the safety profile. The description adds behavioral context beyond annotations by explaining the keyword search across fields and the pure-filter behavior when query is omitted, which is useful for invoking the tool correctly.

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 primary function, and every sentence adds value. The first sentence states the core purpose, and the second provides a practical usage tip and lists supported filters. No wasted words.

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 the tool has 10 parameters and no output schema, the description covers the main purpose and usage nuance, while the schema documents all parameters. It does not mention pagination or return format, which would be helpful given the page and pageSize parameters, so it is not a 5.

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% and each parameter has a description, so the baseline is 3. The description adds meaning by clarifying how query and filters interact (e.g., 'omit query to use as a pure filter') and by specifying the search scope (subject, sender, body), which goes slightly beyond the schema descriptions.

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 searches emails by keyword across subject, sender, and body, and also supports filters. It is specific about the resource (emails) and the action (search), but it does not explicitly differentiate from sibling tools like list_emails or get_emails, so it misses the top score for sibling distinction.

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 usage context, including how to use it as a pure filter by omitting the query, with a concrete example. It does not explicitly state when not to use this tool versus alternatives, but the filter example and supported filters give practical guidance, earning a 4 rather than a 5.

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