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

Annotations already declare readOnlyHint=true, so the 'Read-only RPC' statement is largely redundant. The description does add the control-plane endpoint (POST /rpc/auth_roles) and clarifies that the result covers prefixes the credential can read/write/admin, which is useful but limited behavioral context.

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 and a fragment, all front-loaded and free of waste. Every clause earns its place by stating scope, output meaning, safety class, and endpoint.

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 one-optional-parameter read-only control-plane RPC, the description covers what is returned and that it is read-only. It does not describe the exact result shape or pagination, but no output schema exists and the core completeness need is met.

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?

Schema description coverage is 100% and the single optional parameter (min_capability) is fully documented in the schema with an enum and default. The description does not mention the parameter at all, so it adds nothing beyond the schema; baseline 3 is appropriate.

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 (list), resource (roles/capabilities), and scope (current credential, catalog prefixes it can read/write/admin). The resource is clearly distinct from all siblings (catalog, connectors, drafts, etc.), so an agent can identify it without opening the schema.

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 implies when to use it (to see what the current credential can access) but gives no explicit when-to-use guidance, no exclusions, and no named alternatives among the many sibling list_* tools. Usage is inferable but not stated.

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