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

The annotations already mark the tool as read-only and idempotent, and the description adds valuable behavioral context beyond that: the global rate limit of 10 analyses per hour, the specific 429 error, and explicit guidance not to retry immediately. This is exactly the kind of operational disclosure that helps an agent avoid failure.

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 compact and front-loaded: the first sentence establishes the action and expected output, and the second delivers essential rate-limit and retry guidance. Every clause earns its place, with no filler or repetition of the 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?

The description explains the full workflow and the nature of the result (extracted characteristics and candidate cadastral parcels), which is adequate given that no output schema exists. It could be more precise about the exact return structure, but the rate-limit warning and supported portal context make it sufficiently complete for a single-parameter, read-only tool.

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 schema already fully documents the single required 'url' parameter with 100% coverage. The description adds extra meaning by enumerating accepted sources (SeLoger, PAP, Bien'ici, Le Figaro Immobilier) and implying that the URL must be complete, which goes beyond the schema's terse 'URL complète de l'annonce immobilière'.

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 names a specific verb and resource: it analyzes a French real-estate listing URL, extracts property characteristics, and identifies candidate cadastral parcels by cross-referencing the DPE database. This clearly distinguishes it from sibling tools that work from an address or criteria, since it is URL-driven and includes a multi-step pipeline.

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 use case is clear: this tool should be used when the agent has a full URL from a recognized French listing portal. It does not explicitly name alternative sibling tools or state when not to use them, but the URL-based input and listed portals make the intended context unambiguous.

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