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

Annotations already declare readOnly/idempotent/non-destructive, so safety is covered; the description adds genuinely new behavioral context: the full secret is never returned and is only visible once at creation. That is exactly the kind of non-obvious disclosure annotations cannot carry. It stops short of describing pagination or result ordering.

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 short sentences, front-loaded with the action and the returned fields, followed immediately by the most important caveat about the secret. No filler.

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 parameterless read tool with full annotation coverage, the description supplies everything needed: what it returns and the critical limitation that secrets are unavailable. The absence of an output schema is mitigated by the explicit field enumeration.

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 the baseline of 4 applies. There is nothing for the description to clarify, and it correctly does not invent parameter semantics.

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 ("List the account's API keys") and even enumerates the returned fields (name, prefix, last used), so the agent knows exactly what this yields. It does not explicitly name the sibling clipember_revoke_api_key, but the list-vs-revoke distinction is obvious from the verb.

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?

Usage is implied by the purpose — call this to enumerate the account's keys — but there is no explicit when-to-use, when-not-to-use, or reference to alternatives such as clipember_revoke_api_key. Adequate but leaves routing to inference.

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