ses_list_identities

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

With no annotations, the description carries the full burden. It discloses that the operation lists verified identities and that it covers both email and domains, but it does not explain whether the list is filtered by identityType by default, nor does it disclose return formatting or any potential side effects. 'List' implies a read-only operation, which helps.

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, clear sentence that states the purpose without unnecessary words. Every word contributes meaning.

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 one optional parameter and no output schema, the description is mostly complete: it states what is returned (list of identities). It does not explicitly state the output format, but that is implied. It could mention that identityType is optional, but that's in the schema. Overall, it's sufficient for this simple tool.

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 already fully describes the only parameter (identityType) with a clear description and enum values, so schema coverage is 100%. The description adds no additional parameter meaning, so the baseline of 3 is appropriate.

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 uses a specific verb ('List') and identifies the resource ('SES verified identities') and scope ('all email addresses and domains'). It distinguishes from sibling SES tools like ses_get_identity_verification_attributes or ses_verify_email_identity because it's the only one that enumerates all identities.

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 when to use the tool (when you need to enumerate all SES identities), but it does not provide explicit when-not-to-use guidance or mention alternatives. It does clarify the localization ('in LocalStack'), which gives context but no exclusions.

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