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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is clear. The description adds the plan requirement, which is valuable beyond annotations. However, it doesn't describe the return format or error behavior, but with an output schema present, that is less critical. The description does not contradict annotations, and the plan requirement adds context.

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 sentence that states the action and a key prerequisite. Zero waste, and the core purpose is front-loaded. It could not be more concise while still including the plan requirement.

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?

Given that there is an output schema (though not shown in the input), the return value is already defined. The description covers the essential purpose and the one non-obvious requirement (plan level). It does not mention error cases or idempotency, but annotations cover idempotency. For a simple single-parameter tool, this is nearly complete.

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 schema covers 100% of the parameter (id) with a clear description: 'as returned by list_certificates or create_certificate'. The tool description does not add additional semantics beyond what the schema provides. Since schema coverage is high, baseline 3 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 states a clear verb ('Fetches') and resource ('certificate template by id'), making the purpose obvious. It doesn't explicitly differentiate from sibling tools like get_issued_certificate or list_certificates, but the id-based fetch is distinct enough. A minor gap is not naming the sibling alternative, but the purpose is still clearly stated.

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 mentions the requirement 'Requires the Scale plan or higher', which is a clear usage constraint. It does not explicitly state when NOT to use it or name alternatives, but the id-based fetch implies it's for when you have a specific id, which is implicit. Could be improved by explicitly saying 'use list_certificates to find ids first', but the plan requirement is useful.

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