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

No annotations are provided, so the description carries the burden. It states this is a list operation, implying read-only behavior, and mentions optional filters. However, it does not disclose return format, ordering, pagination, or any potential side effects, though the simplicity of the tool reduces the need.

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 a single sentence that front-loads the purpose and mentions filters. No wasted words, perfectly concise.

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 simple list tool with two optional filters, the description is largely complete. It states the action, resource, and filter options. It does not detail return values, but no output schema exists, so that is not required. It lacks explicit exclusions or prerequisites, but the tool's simplicity makes them unnecessary.

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 both q and to parameters having descriptions. The description merely restates 'keyword (q)' and 'recipient (to)' without adding new meaning beyond the schema, which is already explicit.

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 sent emails, distinguishing it from read_inbox (received emails) and get_email (single email retrieval). It uses a specific verb 'List' and identifies the resource (sent emails).

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 clarifies the use case (listing sent emails) and indicates optional filters, which implies when it should be used. It does not explicitly mention alternatives, but the context makes it distinct from sibling tools like read_inbox.

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