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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), so the bar is lower. The description contributes a plan/entitlement requirement, which is genuinely useful behavioral context beyond annotations, but says nothing about volume, pagination, or ordering of the returned list.

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 clauses, front-loaded with the verb and resource, then the disambiguation, then the prerequisite. No sentence is redundant and nothing is buried.

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?

An output schema exists, so return-value detail is unnecessary in the description; the description instead supplies the one thing the schema can't — what the resource conceptually is and how it differs from a sibling. Nothing an agent needs to invoke it correctly 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?

The tool takes no parameters, so the baseline is 4. The description correctly avoids inventing filter syntax and instead spends its words on identifying the resource, which is the right trade-off for a zero-arg tool.

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 ('Lists certificate templates') and immediately defines what a template is (the PDF design a learner receives), naming its components. It also explicitly excludes the near-neighbor resource by name, so an agent can distinguish it from list_issued_certificates without opening a schema.

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?

Explicitly states the when-not case ('Not the certificates issued to learners; those are list_issued_certificates') and routes the agent to the correct alternative. It also adds a gating prerequisite ('Requires the Build plan or higher'), which is actionable selection context.

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