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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint and destructiveHint=false, so the safety profile is covered. The description adds one genuinely useful behavioral fact — 'Data is live from the HolidayFox booking system' — signalling freshness, but says nothing about cost/latency of the call or whether prices appear only when dates are supplied.

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?

A single dense sentence that front-loads the core purpose and then enumerates outputs, with no filler. It is long but every clause maps to real returned data, so nothing feels wasted.

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 usefully enumerates the returned fields (amenities, cancellation policy, instant-vs-request booking, unit sizes/prices), which is the right move. It stops short of covering the optional date/party parameters and the call sequence, leaving gaps for a 7-param 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 57% and three optional params (numAdults, numInfants, numChildren) have no description anywhere. The description mentions check-in/out times, minimum stay and price as returned data but never explains that checkinDate/checkoutDate price each unit or how party size affects results, so it fails to compensate for the coverage gap.

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 ('Full facts about one HolidayFox destination') and enumerates the exact fields returned, so the agent knows precisely what this tool produces. It does not, however, differentiate itself from siblings like get_quote or check_availability, which also return stay-related data.

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?

There is no when-to-use guidance: nothing says to call this after search_stays and before get_quote/begin_checkout, nor when check_availability is the better choice. The only routing hint is the schema's note that destinationId comes from search_stays, which is schema-level, not description-level.

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