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

Annotations only declare readOnly/openWorld/non-destructive; the description adds substantial behavior the agent could not infer: bilingual query support, that 'comparison is not booking consent' (a consent boundary), that nextAction must be respected, that null/missing price fields mean unknown, and that each option must be shown with a clickable canonical url. This is exactly the kind of operational context annotations do not carry.

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?

It is a dense single paragraph, but it is front-loaded with the use condition and each sentence carries distinct information (scope, language, exclusions, geography strategy, output presentation, consent boundary). Slightly packed — the output-rendering guidance could arguably be separated — but there is 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 15-parameter, zero-required, open-world search tool with an output schema, the description covers the decision-relevant surface: when to call it, how to choose among the three geography modes, the near-me fallback, and how results should be surfaced. Return-value shape is already covered by the output schema, so nothing material 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?

Schema coverage is 67%, and the description compensates for the geography parameters specifically: provinceUuid means a whole-province search, area means a town, and omitting geography means a national search. That disambiguation is not fully spelled out in the schema and is genuinely useful, though several other parameters (limit, partySize, delivery, priceUnit) get no added meaning in the description.

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 (find/compare/book services and providers in Costa Rica) and immediately bounds it with exclusions: 'not general advice, job vacancies or services outside Costa Rica.' That scope statement cleanly separates it from siblings like wellfred_search_classes and wellfred_search_events without the agent needing to open any 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?

It gives explicit when-to-use triggers ('finding, comparing or booking', customer describes a need without naming services or WellFred), when-not conditions (job vacancies, out-of-country, general advice), and a procedural rule for the near-me case ('ask for the area first'). It also routes to a sibling (wellfred_resolve_location) for ambiguous locality names, so alternatives are named rather than implied.

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