search_emails

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

With no annotations, the description carries the full burden for behavioral disclosure. It does not mention that the search is read-only, what the return format is, or any limitations (e.g., default folder, count). The description is minimal and adds no behavioral context beyond what's already implied by the tool name.

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 exceptionally concise: two short sentences that front-load the core purpose and quickly specify a usage pattern. No redundant or filler content.

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 6 optional parameters and no output schema or annotations, the description is adequate but leaves gaps. It does not describe the shape of results (e.g., full emails vs. headers) or mention default values, though these are partially in the schema. It covers the main usage but lacks richness.

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?

The schema covers all parameters at 100%, so the baseline is 3. The description adds semantics by explaining the query parameter as an alternative to combining from/subject/since filters, which is useful strategic guidance beyond individual parameter 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's purpose with a specific verb ('Search') and resource ('emails'). It distinguishes the tool from siblings like list_emails and read_email by emphasizing search by various criteria, which is a distinct operation.

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 parameter usage guidance ('Use query for full-text search or combine from/subject/since filters'), but does not explicitly contrast when to use this tool versus list_emails or list_unread_emails. It gives clear context without exclusions, so a 4 is appropriate.

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