mail_list_pending

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

Annotations already indicate readOnlyHint=true and destructiveHint=false. The description adds value by disclosing the return format (list of dicts with specific keys), which is beyond what annotations provide. It does not, however, mention any pagination or rate-limiting behavior.

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 concise: two sentences that front-load the core purpose and provide essential return structure. No unnecessary words or repetition, and every sentence adds value.

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 an output schema (as per context signals), the description's explanation of return fields is redundant but harmless. The description, combined with schema and annotations, fully specifies the tool's behavior for an AI agent to select and invoke correctly.

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% for the single optional parameter 'limit', which is fully described in the schema (default, min, max). The description does not add any additional semantic information about the parameter beyond what the schema already conveys.

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 lists unread forwarded emails in Hermes's inbox, sorted newest first. It uses specific verbs ('list') and resources ('unread forwarded emails'), distinguishing it from siblings like mail_search (broad search) and mail_get (single email retrieval).

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 implies the tool is for listing pending (unread forwarded) emails, but does not explicitly state when to use it versus alternatives like mail_search or mail_archive. No guidance on prerequisites or exclusion criteria is provided.

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