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

The description adds valuable behavioral context beyond the annotations: it discloses that the tool returns availability, total price, capacity check, and conflicting bookings, and explains the fee structure (host receives 100%, 3% guest fee). This goes beyond the readOnlyHint and destructiveHint annotations, providing a clearer picture of the tool's behavior.

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 three sentences long, with no unnecessary words. The first sentence states the purpose, the second lists the outputs, and the third provides fee details and a critical usage order. Each sentence earns its place, making it concise and well-structured.

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 description provides sufficient context for an agent to understand what the tool does, what it returns, and the pricing model. It also includes the key prerequisite relationship with the booking tool. While there is no output schema, the description's list of return values and fees covers the essential information, though it omits details like error conditions or response structure.

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?

The input schema has 100% coverage with descriptions for all parameters, so the baseline is 3. The description adds no additional meaning to the parameters themselves; it only mentions "specific dates" and "capacity check," which are already implied by the schema fields. Thus, it does not exceed the baseline.

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 the tool's purpose: "Check real-time availability and pricing for a vacation rental property on specific dates." It also distinguishes itself from the sibling tool 'book_vacation_rental_direct' by explicitly noting it should be called before that tool, making the purpose and scope clear.

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 gives explicit usage guidance with "Always call this BEFORE book_vacation_rental_direct," which indicates when to use the tool. However, it does not mention contexts where the tool should not be used or provide alternative tools for other scenarios, so it lacks complete when-not/alternatives coverage.

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