search_emails_metadata

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

No annotations, so full burden on description. Discloses that the query searches body text server-side (sensitive operation) but only returns metadata envelopes, never preview or body excerpts. This clearly sets expectations for privacy and security.

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?

Two concise sentences. First sentence defines tool and output fields; second explains behavioral nuance and usage. No redundancy, front-loaded with key info.

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 3 parameters, no output schema, and no annotations, the description fully covers what the tool does, its relationship to sibling, and behavioral constraints. Lists output fields, fulfilling context completeness.

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 descriptions for all three parameters (query, limit, ascending). Description adds minimal extra meaning beyond the schema (e.g., that query searches across subject and body). Baseline 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?

Clearly defines it as a variant of search_emails that returns only metadata fields (id, threadId, subject, from, etc.). Distinguishes from its sibling search_emails by specifying the reduced output but same server-side search logic.

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?

States when to use: when a content match is needed but body fragments must not be surfaced. Implicitly contrasts with search_emails for when body is needed. No explicit when-not-to-use, but context is sufficient.

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