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

With no annotations provided, the description carries the full burden, and it delivers meaningful behavioral context: 'never material' reassures the caller that secrets won't be exposed, and 'Auth required' sets expectations about authorization. It could go further by noting what happens on auth failure or whether results are paginated, but for a zero-parameter list, these two clausal disclosures address the most critical risks.

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 a model of efficiency: a nine-word sentence followed by a two-word fragment delivers purpose, scope, return-type caveat, and auth requirement. Every phrase earns its place, and the key behavioral qualifier 'never material' is placed front-and-center after an em-dash for readability.

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 tool has zero parameters, no output schema, and no annotations, the description covers the essential ground: what it lists, what it returns, and what's required (auth). The only minor shortfall is the absence of any mention of pagination, ordering, or empty-credential-set behavior, but for a tool this simple the description feels nearly complete.

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?

There are zero parameters, and per the rubric, a tool with no parameters earns a baseline of 4 since there is no schema gap for the description to compensate for. The description adds no parameter-related content, but none is needed because the schema is trivially complete at 100% coverage.

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 uses a specific verb+resource construction: 'List stored venue credentials' with a scope qualifier 'metadata only, never material' that precisely defines what the tool returns. This clearly differentiates from siblings like store_pm_credential and revoke_pm_credential, which are visibly different operations on the same resource type.

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 provides implicit usage context by noting 'Auth required' and clarifying that only metadata is returned, which hints at a safe, non-secret read operation. However, it never explicitly states when to prefer this over alternatives like check_pm_order or list_pm_orders, nor does it mention exclusions. The guidance is adequate but relies on the sibling names to convey the surrounding workflow.

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