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

Annotations already declare readOnlyHint=true and destructiveHint=false. The description adds that token values are never returned and that user auth is required, which are behavioral traits not covered by annotations. This adds value without contradicting.

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 sentences with zero redundancy. Front-loaded with the resource and fields, then the crucial security note about token values never being returned.

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 list tool with no parameters and no output schema, the description covers everything an agent needs: the resource, the returned fields, the auth requirement, and the key security caveat. Nothing essential is missing.

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?

Zero parameters, so schema coverage is trivially 100%. The description adds nothing about parameters (none exist), but the baseline for 0-param tools is 4, and the description appropriately focuses on return fields and auth.

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+resource: 'List the current user's API keys'. Specifies exactly which fields are returned (id, name, createdAt, expiresAt). Distinct from siblings like ethora-api-key-create and ethora-api-key-revoke by the clear read-only action.

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?

Implies usage: for listing keys of the current user, and notes auth requirement. Does not explicitly contrast with create/revoke, but the action is unambiguous and the scope ('current user') is clear.

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