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

With no annotations, the description carries the full burden and does disclose a real behavioral trait: these destinations are bespoke and built to order, so price and departure-date fields do not apply — a genuine gotcha an agent would otherwise misread. It does not cover output shape or ordering, which keeps it short of a 5.

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 tight sentences: purpose first, then the pricing/date caveat, then sibling routing, then the triggering question. Every clause earns its place with no filler.

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 parameterless read list with no output schema and no annotations, the description supplies what is needed: what it returns (destinations with their grounds and places), why no price/date appears, and which alternatives to use. An agent can call it correctly from this text alone.

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 zero parameters, so per the rubric the baseline is 4; there is no parameter syntax the description needs to compensate for. The description appropriately explains what the listing contains instead of trying to document nonexistent inputs.

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 and resource ('List every destination Follow On Tours covers for cricket') plus the scope of what each entry contains (grounds and places). It explicitly names the siblings it is not — list_tours and list_golf_trips — so an agent can route correctly 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 says when to use it ('when asked where Follow On Tours goes, or whether they cover a country or a ground') and when not to, pointing to list_tours for on-sale tours and list_golf_trips for golf. Nothing is left to inference.

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