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

Annotations already declare readOnly, idempotent, non-destructive, open-world behavior, so the description is not carrying the safety burden. It still adds real operational context beyond them: dates are Europe/Paris, price is the final customer-charged amount in euros with two decimals, resort matching ignores case and accents, and booking is only possible via the returned URL.

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 carrying a distinct fact, with the core purpose front-loaded before the operational caveats. The clipped telegraphic style ('Dates and times are Europe/Paris.') is efficient, though a little more connective structure would read better without adding length.

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-value explanation is legitimately omitted, and the booking-URL note covers the key downstream action. However, for a nine-parameter open-world search with no required parameters, the description leaves unclear what an unfiltered call returns and how party, duration, and language should be formed, which is a meaningful gap.

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% across nine parameters, so the description must compensate and it only partly does. It clarifies the date/from/to timezone, the sport vocabulary (ski, snowboard, mountain-bike), and resort normalization, but party, duration, language, and instructor are left entirely unexplained, including their string-or-number union types.

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 states a specific verb and resource: searching real private ski, snowboard, and mountain-bike lessons on Yeww. That is far more concrete than the name alone and implies a marketplace search distinct from the sibling get_instructor, though it never explicitly contrasts the two.

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?

Usage is implied rather than stated: an agent can infer this is the entry point for finding bookable lessons, and the closing sentence notes that booking happens only on the returned Yeww booking URL. There is no explicit when-to-use versus get_instructor, no note on what to do when no results match, and no guidance on which of the nine optional filters to combine.

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