List Emails

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

With no annotations, the description discloses that it returns a paginated list of recently sent transactional emails with specific fields (to, subject, status, etc.). This covers the main behavioral aspects, but does not mention rate limits, authentication requirements, or default ordering. However, given the tool's simplicity and schema coverage, it is adequate.

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?

Well-structured with markdown headings and bullet points. Front-loaded with purpose. Every sentence provides value without redundancy. Efficient use of space.

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 3 optional parameters and no output schema, the description covers all necessary aspects: purpose, usage guidelines, not-for cases, return fields, and workflow. It is complete and self-contained.

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 does not add additional meaning beyond the schema's parameter descriptions. The mention of pagination is implicit but not elaborated in terms of parameter usage.

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 it lists recently sent transactional emails with metadata, and explicitly distinguishes from broadcast campaign listing via sibling tool list-broadcasts. The verb and resource are specific and 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 (check sent emails, delivery status, find email ID) and when not (not for broadcast campaigns, not for composing). Also provides alternative tool (list-broadcasts) and suggests a workflow (list-emails then get-email).

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