list_roles

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

Annotations already declare readOnlyHint=true and openWorldHint=true, meaning the tool is safe and may return dynamic data. The description adds value beyond annotations by stating the required permission (EMPLOYEES_R) and specifying the returned fields, which is useful for the agent. No contradictions with annotations.

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 concise and front-loaded: the first sentence clearly states what it does, and the second sentence adds the permission requirement. No wasted words or redundant information, making it highly efficient.

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 that the tool has no parameters, is a simple list operation, and has an output schema, the description is complete. It states the purpose, the permission needed, and the output format sufficiently for an agent to select and 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 tool has zero parameters, so the baseline is 4. The description does not need to explain parameters, and there are none to elaborate on. The schema coverage is trivially 100%, and the description adds no param info because no params exist.

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 ('Return') and resource ('the merchant's employee roles'), and even specifies the output fields ('name + system role category'). This clearly distinguishes it from sibling tools like list_employees or get_employee, which focus on employee data rather than roles.

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 the tool (whenever you need employee roles), and it provides the authorization prerequisite (EMPLOYEES_R). However, it does not explicitly name alternatives or when-not-to-use conditions, but since there is no other role-listing sibling, the use case is clear.

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