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

Adds real behavioral context beyond the annotations: results are restricted to current public classes, and 'Results do not establish seat availability' warns the agent not to treat hits as bookable — a meaningful caveat given a sibling wellfred_service_availability exists. It does not explain why readOnlyHint=false on what reads as a pure search (e.g. logging/side effects), which is the one unexplained trait.

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?

Four short sentences, each doing distinct work: trigger, scope/alternative, parameter precondition, and a result caveat. The selection guidance is front-loaded in the first clause.

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 values need no explanation, and the description covers trigger, scope, sibling routing, origin sourcing, and the seat-availability caveat. What's missing is guidance on result volume (limit default 5, max 20) and radius behavior when origin is supplied, which matters for a nested-object search tool.

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 only 50% (limit and origin.lng are undocumented), so the description should carry more weight. It does clarify that origin should be a resolved locality center and that the term excludes place names, but it says nothing about limit semantics, distance defaults, or how term and origin combine — leaving half the surface to the schema alone.

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 ('Search ... WellFred classes'), plus a geographic scope (Costa Rica) and a currency/visibility constraint (current public only). The second sentence explicitly contrasts it with the services path, so the agent can separate it from wellfred_search_services without opening either 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?

Gives an explicit when ('customer specifically wants classes in Costa Rica'), a when-not with the alternative named ('use services for general provider/service needs'), and a precondition for the origin parameter ('use a resolved locality center if the customer supplied an area'), which routes the agent through wellfred_resolve_location first.

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