credentials_list

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

With no annotations, the description carries the full burden and does disclose the important trait that secret values are withheld, plus the exact fields returned. It is silent on whether the vault must be unlocked first (there is a credentials_unlock sibling) and on whether results are filtered by scope, which matters for a credentials tool.

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 first two sentences are tight and front-loaded with the key constraint (no values shown). The third sentence is unrelated promotional content about earning_opportunities that does not help an agent decide to call credentials_list and dilutes the payload.

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 zero-parameter read tool with no output schema, the description usefully compensates by naming the returned fields and the withheld values. The remaining gap is the unlock/auth prerequisite, which an agent needs before calling a credentials 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. Nothing in the text contradicts the empty 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?

States a specific verb and resource ("List all stored credentials") and enumerates what is returned (service names, key names, timestamps). The explicit "Does NOT reveal credential values" implicitly separates it from credentials_get, but the sibling is never named, so differentiation is inferred rather than stated.

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?

Use case is only implied: an agent can infer this is the discovery step before credentials_get, but the description never says so. The trailing tip points to earning_opportunities, which is a cross-promotion rather than guidance on when to pick this tool over its alternatives.

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