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

Annotations already cover read-only/idempotent/closed-world, so the description adds genuinely new behavior: entries come in two states, 'dates listed' or 'link only', and link-only records carry no readable calendar so the agent must redirect the user to the organiser's website. That is real operational context not available elsewhere.

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 that carry real information with little padding, but the phrasing is awkward — the embedded quotation of 'dates listed' is clumsy and the opening sentence lacks a verb, making it read like a data dictionary entry rather than a tool instruction.

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?

With only two optional enum params and no output schema, the description covers the necessary ground: what the list contains, the two record states, and how to act on them. It stops short only on whether the result is paginated or what fields each entry carries.

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%, and the description fills the gap for `region` by clarifying it is the region of the circuits the organiser runs at, not the organiser's own location — a meaningful disambiguation. The `type` values are already enumerated in the schema, so no further credit there.

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 the resource precisely (track-day organisers, schools, clubs) and describes the two listing modes, which lets an agent separate it from list_circuits and find_track_days. The first sentence is a fragment with no explicit verb, so the 'list' action is only implied by the name.

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 gives filtering guidance ('Filter by the region of the circuits they run at, or by organiser type') and a handling rule for link-only entries, but never states when to choose this over the sibling tools or what prerequisites apply. Usage is inferable rather than explicit.

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