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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, so the safety profile is covered. The description adds genuine behavioral detail beyond the annotations: results are limited to actually issued certificates and include the public serial. This enriches what the agent knows about the tool's behavior without contradicting the 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?

Two sentences with no filler. The core purpose and the scope qualifier ('actually issued') come first, and the sibling distinction is packed into the second sentence. Every phrase earns its place.

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 list tool with a full output schema and all parameters documented, this description is complete. The sibling distinction removes ambiguity, and there are no missing prerequisites or behavioral caveats an agent would need to call 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?

Schema description coverage is 100% – every parameter has a meaningful description, so the structured data already explains limit, offset, courseId, and identityId. The description doesn't add parameter-specific detail, but it doesn't need to; baseline 3 is appropriate when the schema carries the burden.

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 states a specific verb ('Lists') and resource ('certificates this workspace has actually issued'), and adds a distinguishing detail ('with the public serial printed on each one'). It also explicitly contrasts with list_certificates, making it immediately clear what this tool does and does not do.

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 explicitly names the closely related sibling (list_certificates) and explains the distinction: issued certificates vs certificate designs. This gives an agent clear routing guidance without needing to inspect either schema.

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