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

Annotations already declare readOnlyHint=true, openWorldHint=true, and destructiveHint=false. The description adds critical behavioral context beyond these hints: the tool returns a URL that pre-fills a form rather than returning results directly, requiring the user to click Search to see live pricing and availability. This is meaningful disclosure of how the tool operates.

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 two sentences, front-loaded with the core purpose, and contains no fluff. It efficiently conveys the tool's function, return value, and required next action.

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 is complete for this simple tool: it explains the tool's output (a URL), the follow-up action needed (click Search), and the scope (160+ rental companies). With comprehensive parameter schemas and safety annotations, the description covers the essential context without needing to document return values since there is no output schema.

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 parameters are already documented with types and examples. The description adds a general framing—'pre-fills the search form with your trip details'—but does not add per-parameter semantics beyond what the schema already provides. Given the high schema coverage, a baseline score of 3 is appropriate.

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: 'Search campervan and motorhome rentals.' It also explains the unique return behavior—a URL that pre-fills a search form—which distinguishes it from the sibling tool list_locations.

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 provides clear context for when to use the tool (to search campervan and motorhome rentals) and includes an actionable workflow step: 'Click Search on the page to see live results.' It does not explicitly mention alternatives or exclusions, but the usage context is clear enough.

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