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

readOnlyHint=true already signals a safe read, and the description adds genuinely new behavioral information: the response excludes secret key values, which is exactly the kind of disclosure an agent needs to reason about output handling. It stops short of noting ordering, pagination, or whether revoked keys are included.

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?

Front-loaded with the operation and its key output caveat, then a clearly separated ACCESS block. Slightly chatty with the parenthetical UI path, but every sentence carries actionable information.

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?

An output schema exists, so return shape needn't be described, and the auth barrier — the main obstacle to a successful call — is fully covered. Only minor gaps remain (pagination/ordering, scope of keys included), which are low risk for a zero-parameter list 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 tool takes zero parameters, so there is nothing for the description to disambiguate; baseline 4 applies. The absence of any filtering argument is also implicitly communicated by 'List all'.

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?

States a specific verb and resource with scope ('List all API keys for the authenticated account') and adds a materially distinguishing detail: key metadata is returned, not secret key values. It implicitly separates itself from create_api_key/revoke_api_key/get_api_key_usage, though it never names get_self_api_key as the singular-key alternative.

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 ACCESS block gives a concrete prerequisite (Proof account) and a remediation path (authenticate the client, or start_login then retry), which is real usage context. However, it says nothing about when to prefer this over get_self_api_key or get_api_key_usage, so sibling selection is left to inference.

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