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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety and scope are covered structurally. The description adds useful context that the result is a per-event listing containing a numeric subject_id keyed to a detail tool, but says nothing about pagination, volume, or ordering for a listing endpoint.

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 tightly packed sentences, front-loaded with the primary output and followed by the navigation contract. Every clause earns its place with no redundancy.

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 shape needn't be described, and the description covers the input source and downstream destination. For a simple one-param listing tool this is nearly complete, missing only minor behavioral notes like pagination.

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% with one parameter, so the schema already documents CategoryID. The description restates the provenance of category_id ('from psa_ticketfacts_categories') but adds no format or constraint detail beyond the schema, 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?

The description names a specific verb+resource combination ('Every event PSA TicketFacts lists for one category') and explicitly scopes it to a single category. It distinguishes itself from siblings by directing the agent to psa_ticketfacts_subject for the full page and psa_ticketfacts_categories for the id source.

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?

It tells the agent where category_id comes from (psa_ticketfacts_categories) and what to do with the returned subject_id (pass to psa_ticketfacts_subject), effectively documenting the workflow chain. It stops short of stating when NOT to use it or other alternatives, but the context is clear.

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