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

Beyond the readOnlyHint annotation, the description discloses concrete behavior: the pricing model switches between total stay price with cleaning included (when checkIn/checkOut are supplied) and the lowest nightly price over the next 60 days (when they are not). It also states what every listing exposes (registration number, map-derived town, measured distances), which is the sort of return-shape context annotations cannot 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?

Front-loaded with purpose, then result content, then filters, then the conditional pricing rule, then the no-place tip. Four sentences and every one carries information; only the enumeration of what each listing shows is slightly dense but it is the most decision-relevant part.

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?

With no output schema, the description correctly spends its space describing what results contain and how prices are computed, which is what an agent needs to interpret the response. Remaining gaps are minor: no mention of result limits/pagination, whether place must be an exact municipality string, or that locale affects returned text, but none block correct invocation.

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 80%, so place, locale, checkIn and checkOut are already documented. The description still adds real meaning beyond the schema by explaining the semantic consequence of supplying versus omitting checkIn/checkOut and of omitting place, which the schema's bare format hints do not convey.

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 opens with a specific verb and resource ("Search holiday rentals") and immediately characterizes what a result contains: registration number, derived town, measured beach/airport distances. That makes the tool's output identity distinct from get_stay, get_availability and prepare_booking, though no sibling is named explicitly, which keeps it just short of a 5.

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 through the filter list ("Filter by town, dates and guests") and one genuinely useful call pattern is given: calling without a place reveals which destinations exist. However, there is no statement of when to prefer this over get_availability or get_stay, and no note that dates must be paired or ordered, so the agent must infer the routing.

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