emails_list

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

With no annotations, the description partially discloses behavior by noting the tool does not include message body. It does not clarify whether it is read-only (implied by 'List') or describe pagination/return format, but the disclosed limitation is significant and helpful.

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?

Two sentences, front-loaded with the verb and resource, and no filler. The second sentence efficiently communicates a critical limitation and points to the correct alternative, earning its place.

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 list tool with a rich schema (5 documented parameters) and no output schema, the description adequately covers the core purpose and the most important output characteristic (no body). It could mention that it returns a list of summaries, but the pointer to email_get covers the main follow-up need.

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 description coverage is 100%, so the description adds no additional parameter meaning beyond what the schema already provides. It does not clarify parameter interactions, but the baseline of 3 is appropriate since the schema fully documents each parameter.

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 a specific action ('List') and resource ('outbound SMTP emails'), immediately distinguishing this from other tools like email_get (which retrieves full details). It also specifies the scope (outbound) and the key omission (no body), making the purpose 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?

The description explicitly points to email_get as the alternative for full message body details, providing a clear when-not-to-use signal. It lacks broader context on when to prefer this over messages_list, but the core alternative is addressed.

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