Search email messages

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

No annotations are provided, so the description must carry the behavioral disclosure. It adds notable behaviors: full-text scope across fields, relevance ranking, optional folder scoping. It does not mention page limits, but the top parameter is documented. The description gives enough context for a search operation without contradicting any annotations.

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 sentences, front-loaded with the core function, and no redundancy. Every clause earns its place, making it an exemplar of concise tool documentation.

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 search tool with a simple parameter set and no output schema, the description covers the main functionality, adds an explicit alternative, and clarifies optional folder scoping. It omits pagination details, but the top parameter is documented in the schema, so the description is sufficiently complete for practical use.

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%, so baseline is 3. The description adds context by noting 'Optionally scope the search to one folder,' giving extra meaning to the folder parameter. It does not elaborate on top or query beyond schema, but the added folder context justifies a 4.

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 it performs full-text search across mail fields (subject, body, sender, recipients, attachments) and specifies the ranking mechanism (relevance). It also distinguishes itself from sibling list_messages by contrasting free-text search against structured filtering, making the purpose 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?

Explicitly states when to use (free-text search) and when not to (structured filtering without free-text) and names the preferred alternative (list_messages). This gives the agent clear decision-making guidance.

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