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

Beyond the readOnly/idempotent annotations, the description discloses non-obvious behavior: limit and cursor are ignored, there is no pagination, the response is 'one short response,' and the catalog is a fixed static list. It also specifies the exact return shape, which matters because there is no output schema.

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 dense but every sentence earns its place: purpose, legal-source status, return shape, and non-pagination are all stated without repetition. The only minor awkwardness is 'the settings UI files that permission under,' but it does not undermine clarity.

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 tool with zero required parameters, strong annotations, and no output schema, this description is complete. It explains what the tool returns, why pagination is irrelevant, and how the results relate to role creation/update. An agent has everything needed 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?

Schema description coverage is 100%, and the schema already fully explains that limit and cursor are accepted for compatibility and ignored. The description reinforces this but does not add new parameter-level meaning beyond what the schema provides, so the baseline of 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?

The description states a specific purpose: it is 'the complete catalog of permission strings a role can grant,' returning each with a human label, description, and group. This clearly distinguishes it from sibling list tools (e.g., connection__list, role__list) and positions it as the reference source for permission values.

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?

It explicitly says this is 'the ONLY legal source of values for role.create and role.update — names not in this list are rejected.' This tells the agent exactly when to consult this tool and that no alternative source is valid.

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