Search Emails

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

Discloses server-side IMAP SEARCH behavior and local filtering for hasAttachment, plus folder limit (capped at 20). Adds significant value beyond annotations (readOnlyHint, openWorldHint).

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?

Four concise sentences covering search criteria, behavior, return type, and alternative. Front-loaded with key information; no superfluous text.

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 21 parameters, no required params, and output schema present, description adequately covers scope, behavioral nuances, and routing (account_id). Guides agent effectively.

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?

High schema coverage (86%) gives baseline 3. Description adds grouping of filter types and special behavior for hasAttachment, enhancing understanding. Does not repeat schema details but adds context.

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 states verb 'Search' and resource 'emails', lists specific filter criteria (sender, recipient, subject, etc.), and distinguishes from siblings like get_emails and get_email_by_id via folder usage and return type.

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 explains when to use folder vs folders (including wildcard), notes local filtering for hasAttachment, and directs to get_email_by_id for full content. Provides clear context for use.

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