list_agent_identities

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

With no annotations provided, the description carries the full burden. It discloses that the raw key is never stored, only its SHA-256 hash is retained, which is a security-relevant behavioral trait. It also lists the fields returned (name, key prefix, dates, rotation history, revocation status). It does not mention permissions or side effects, but for a list operation, the disclosure 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?

The description is three sentences long: the first states the primary purpose, the second details the fields, and the third provides a usage guideline for a sibling tool. Every sentence adds value without redundancy or wasted words.

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 simplicity of the tool (0 parameters, no output schema), the description is complete. It explains the tool's function, the structure of each identity, and a behavioral note about key storage. It also mentions the sibling for creation, covering the necessary context for an agent to use the tool 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?

The input schema has 0 parameters, so schema coverage is 100% and the baseline is 4. The description adds context about what each identity contains (e.g., key prefix, creation date, last-used timestamp, rotation history, revocation status, and the hash note), which helps the agent understand the output format despite no output schema.

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 'List all agent machine identities' with a specific verb ('List') and resource ('agent machine identities'). It distinguishes from the sibling 'create_agent_identity' by being a read-only operation, and the purpose is 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 directs to use 'create_agent_identity' for issuing new identities, providing an alternative for a related operation. However, it does not explicitly mention when not to use this tool relative to other siblings like 'revoke_agent_identity' or 'rotate_agent_identity', though the purpose is clear enough to infer that this is for listing only.

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