credential.list

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

No annotations are provided, so the description carries the full disclosure burden. It usefully signals that only non-secret account names are returned, but it does not state whether authentication is required, how the relevant profile is determined (the schema takes zero parameters, yet the text says 'a profile'), or how results are scoped.

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 terse, front-loaded sentences with zero filler, and the safety-relevant fact is placed inline rather than buried. It is arguably over-terse sentence-fragment prose, which slightly limits clarity but nothing is wasted.

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 no output schema, the description adequately sketches the return content (platforms and account names) and its non-secret nature. However, with no annotations and no output schema, the unexplained profile-scoping mechanism leaves a real gap for an agent deciding how to invoke it 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 schema declares zero parameters and coverage is 100%, so per the rubric the baseline is 4. There are no parameters whose semantics the description could add or omit, and it correctly makes no parameter claims.

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 fragments describe the returned resource (platforms a profile can log into, plus account names) but never state a verb such as 'list', so the tool's action must be inferred from the name 'credential.list'. It does differentiate content-wise from credential_fill/credential_new/credential_store and secret_list by emphasizing 'never secrets', which helps an agent tell it apart from secret_list.

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?

There is no statement of when to use this tool, no prerequisites, and no named alternatives among the many sibling tools (secret_list, credential_fill, credential_store, passkey_list). The only adjacent guidance is the implicit 'never secrets' boundary, which hints at a read-only metadata tool but does not say when to choose it.

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