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

Goes well beyond the readOnly/openWorld annotations: discloses page window (1-20, ~30 results), that a total count and town average price with 1- and 5-year change are returned, that data comes via a residential proxy, and the exact $0.002 USDC x402 pricing with failed calls free.

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?

Front-loads the source and scope, then packs return fields and pricing efficiently; the long field enumeration is dense but each clause carries information, with only mild redundancy against the output schema.

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?

Covers source, pagination limits, pricing and payment rails; the field list duplicates what the output schema already provides, so it is complete but slightly redundant rather than optimized.

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 page, type and place are already documented with defaults and examples; the description adds no parameter-level guidance beyond the schema 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?

States a specific verb-resource pair (homes for sale or rent in a town from SeLoger France) and enumerates the returned fields, so an agent can distinguish it immediately from the many other real-estate 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?

The description implies context (French town slugs, seloger.com source) but never states when to prefer this over close siblings such as realestate_bienici_real_estate or realestate_immowelt, nor any exclusions.

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