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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds genuinely new context: the required credential scope (`full_access`) and the underlying endpoint/operationId, which helps with tracing and permission failures. Pagination behavior is left entirely to the 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?

Three short lines, front-loaded with the purpose, then the auth requirement, then the endpoint mapping. No filler, though the endpoint/operationId parenthetical is more useful to a developer than to an invoking agent.

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 zero-required-param, read-only list tool with a fully documented schema and complete annotations, nothing an agent needs in order to call it correctly is missing; the one non-obvious gating fact, the API key tier, is stated.

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% – after/before/limit are each documented including the mutual exclusion of the cursors. The description adds nothing about parameters, so the baseline 3 applies.

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 API keys') that is unambiguously distinct from the create_api_key and delete_api_key siblings. It does not explicitly name those siblings, so it stops short of active differentiation.

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 prerequisite 'Requires a `full_access` API key' is a real usage constraint that tells an agent whether it can call this at all. However, there is no guidance on when to use this versus the create/delete API key tools or how pagination is expected to be driven.

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