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

Annotations already declare readOnly, idempotent, non-destructive, so the safety profile is covered. The description still adds real behavioral context beyond them: results are filtered to rate plans that have availability on every night for the party, prices are in minor currency units, and searches are bounded to 1-30 nights and check-in within 365 days.

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?

Three sentences, front-loaded with the usage trigger, then what is returned, then constraints and the exclusion. No filler or redundancy; each sentence carries distinct information.

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 an output schema already present, the description need not enumerate return fields. It supplies the scope, the availability filter semantics, currency-unit convention, and date-range limits, which is everything needed to call the tool correctly.

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 100%, so every parameter (dates, headcounts, hotelId format) is already documented in the schema. The description's date-window constraints largely restate what the schema says, and it adds no new syntax or party-composition detail. Baseline 3 applies.

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 resource and scope: it returns room types and rate plans with a free room every night for the party, plus inventory counts and prices. The filtering semantics ('free room every night') are more precise than the title alone. It does not name any sibling (e.g. list_daily_rates, list_rate_plans) as the adjacent alternative, so it falls short of full sibling differentiation.

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?

It gives a concrete trigger ('when someone asks if rooms are free for certain dates or what a stay would cost') and a negative boundary ('Not for making a booking'). It does not, however, steer the agent toward or away from any actual sibling tool that overlaps on rates or room lists.

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