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

Annotations already indicate readOnlyHint=true, and the description's 'List' aligns. The description adds the requirement that the credentials feature must be enabled, which is useful behavioral context. However, it does not elaborate on what happens if the requirement is unmet or describe the response format, leaving some gaps.

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 single, front-loaded sentence that states the action and a key prerequisite without any redundancy or fluff. It is highly efficient and easy to parse.

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 simple read-only tool with no parameters, the description is mostly complete. It conveys the purpose and a key requirement. Since there is no output schema, it would be better to explicitly state what is returned, but the phrasing 'List your explicit capability grants' implies the return value is the list. Minor gap on error behavior.

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 schema trivially covers 100%. The baseline for 0 parameters is 4, and the description does not need to explain parameter semantics. It adds no unnecessary details, which 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 clearly states the verb (List) and the resource (your explicit capability grants). It distinguishes from the sibling get_capabilities by scoping to 'your' grants, which is a specific and unambiguous purpose.

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 no guidance on when to use this tool versus alternatives like get_capabilities. It only mentions a prerequisite (credentials feature enabled), but does not clarify scenarios where one would prefer this tool over others or when not to use it.

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