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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, covering the safety profile. The description adds that it returns exact availability, total price, and a booking link, which is useful context beyond annotations. It doesn't mention open-world behavior (e.g., prices may change), but that is already conveyed by openWorldHint=true. The description adds value without contradicting annotations.

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?

The description is a single, well-structured sentence that front-loads the core function (availability + price) and includes the key output (booking link). No wasted words; it is concise and immediately informative.

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?

The tool is simple (3 required params, read-only, no nested objects) and has an output schema that documents return values. The description covers the main purpose and output. The only gap is the undefined 'listing' parameter, but given the simplicity and rich annotations, the description is largely complete. A score of 4 is justified.

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 67%: checkin and checkout have descriptions, listing does not. The tool description itself adds no parameter-specific details beyond the schema. The baseline for high coverage is 3, and since the description contributes nothing about parameters, this score is appropriate. The listing parameter remains undocumented in both schema and description.

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 clearly states a specific action: check exact availability and total price for one listing with concrete dates, and includes the direct booking link. This distinguishes it from sibling tools like search_listings (which searches multiple listings) and get_listing_details/policies/faq (which cover other aspects). The verb+resource are explicit.

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?

The description implies usage when the user has a specific listing and concrete dates, which is a clear context. However, it does not explicitly mention alternatives or when not to use it, nor does it contrast with search_listings. The guidance is implied but not spelled out, so a score of 4 is appropriate.

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