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

Annotations already declare readOnly, idempotent, non-destructive, closed-world. The description adds genuinely new behavioral context: the session is token-scoped, the credential is private, and credentials are never placed in URLs or echoed in errors. That security/side-channel disclosure goes beyond the annotations, though return behavior is still unstated.

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 tight sentences, front-loaded with the core purpose before the auth mechanics. Little waste, though the credential/header instruction could be trimmed into a single imperative.

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 read-only observation tool with no output schema, the description never hints at what the certification state contains, so an agent cannot anticipate the result. Annotations cover the safety profile and one of two params is documented, so this is adequate but leaves a real gap around return content.

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 coverage is 50%: the credential parameter is documented as "Private v5c_ capability for one assigned version" while the required id is not described at all. The description reinforces that the credential is private and token-scoped, adding marginal meaning, but does not clarify what the id identifies (session id, version id, etc.), leaving half the parameter surface uncompensated.

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 and resource: "Observe your token-scoped independent certification session." An agent can tell this is a read/observe operation on a certification session. However, it never differentiates itself from the crowded certification family (certify_status, certification_task, certification_replay, claim_certification), so the boundary is left to inference.

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 second sentence gives an authentication instruction (credential argument vs Authorization header), which is setup guidance rather than when-to-use guidance. There is no statement of when this tool applies versus certify_status or certification_task, and no exclusions or prerequisites for the session itself.

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