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

Annotations already declare read-only and open-world behavior. The description adds valuable operational context beyond annotations: it reads from embedded JSON with no public API, returns only the first results page, costs $0.002 per successful call via x402, and failed calls are not charged. This is strong transparency, though it doesn't cover rate limits or pagination behavior beyond the first page.

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 tight sentences: the first front-loads purpose, source, and returned fields; the second covers data-source behavior and cost. Every sentence earns its place with no filler.

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?

Given the presence of an output schema and annotations, the description covers the essential extras an agent needs: data source, payment model, failure behavior, and the first-page limitation. The only minor gap is not explicitly restating the limit parameter's effect, but the schema handles that.

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 100%, so the single 'limit' parameter is fully documented in the schema. The description doesn't elaborate on the parameter or add syntax/format details beyond what the schema provides, so the baseline 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 identifies the resource (luxury homes for sale in France from luxuryestate.com) and lists returned fields, making its purpose unmistakable. It doesn't use an explicit verb like 'fetch' or 'list', but the retrieval intent is implied and the source differentiates it from siblings.

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 implied by the source and country (luxury French listings), but there is no explicit guidance on when to use this tool versus alternative real-estate tools or when not to use it. No alternatives or exclusions are named.

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