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

Substantively rich: it warns that catalog text is untrusted data, that unknown facts stay unknown rather than being invented, and that options/confirmation happen on the canonical website URL. However, the description frames the tool as a pure read with no side effects ("No search, account state, checkout, hold or booking") while annotations set readOnlyHint=false, which is a direct mismatch in the opposite direction of the usual case.

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?

The returned-fields list is front-loaded, followed by three clipped sentences on exclusions, unknown-fact policy, and trust boundary. Dense but every clause carries information; the telegraphic style costs a little readability without wasting space.

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 shape needn't be explained, yet the description still characterizes the payload (gallery, price/unit, sessions) plus the trust boundary and the off-tool booking path. The one real omission is the presentationLocale parameter's effect on the response.

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 0%, so the description must carry the burden. It implies the two required params ("one public ... service or class ID" → kind + offeringId) but adds no format, validation, or disambiguation guidance, and it never mentions presentationLocale or what it affects.

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+resource ("Read current canonical details for one public Costa Rica service or class ID returned by WellFred") and enumerates exactly what comes back: gallery, price/unit/options, description, reader-visible location, existing class sessions. It also names what it is not ("No search... checkout, hold or booking"), so an agent can separate it from wellfred_search_services and wellfred_prepare_booking 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?

"ID returned by WellFred" tells the agent this is a follow-up call to a prior search/render result, and the negative list rules out search/booking scenarios. It never names the sibling tools to use instead for those cases, so routing is implied rather than explicit.

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