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

Annotations already declare read-only, non-destructive, closed-world, so the bar is lower. The description still adds real operational context: the 18:00 Bangkok day-before booking cutoff, blocked dates, and the fallback behavior of listing the next open dates when the requested date is unavailable.

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?

Two sentences, front-loaded with the core purpose and outputs, followed by fallback behavior. The parenthetical is a dense list but every item carries 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 no output schema, the description usefully enumerates what comes back: seats left, blocked dates, dated prices, and next open dates. It is nearly complete for a read-only lookup tool; only the relationship to booking tools is unstated.

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 all six parameters are already documented, including age banding for adults/children/toddlers and the option label. The phrase 'party price' hints that pricing is computed from group composition, which is marginal added meaning beyond the schema.

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 and resource: live availability plus exact party price for one tour on one date. It implicitly distinguishes itself from search_experiences by scoping to a single tour and date, but never names the sibling or the boundary explicitly.

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 only implied: the caller learns it is the per-date check and that non-bookable dates fall back to a list of next open dates. There is no explicit statement of when to call this versus search_experiences or book_experience, nor any prerequisite such as needing a tour id first.

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