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

No annotations are provided, so the description carries the full burden. It discloses that the tool returns reference rent, upper ceiling, and verdict, but it does not explicitly state whether the operation is read-only, what happens for non-rent-controlled areas, or any other behavioral traits like error handling or data sourcing.

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 concise (two sentences) and front-loaded with the core purpose. The French translation (FR:) adds redundancy by restating the same information, slightly reducing efficiency. Overall, it is well-structured and free of fluff.

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 tool's complexity (7 parameters, no output schema), the description provides useful context: what it does, what it returns (reference rent, upper ceiling, verdict), and when to use it. It does not explain edge cases (e.g., unsupported addresses) or that it specifically applies to 'zones tendues', though it hints via 'zone tendue' in the French sentence. Fairly complete for a well-defined check 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?

Schema description coverage is 100%, so the schema already documents all parameters clearly. The description adds minimal parameter-level detail beyond mentioning 'proposed rent' and 'address', but these are already in the schema. Baseline 3 is appropriate since the description does not enhance parameter understanding beyond the schema.

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?

Description clearly states the tool's function: 'Check whether a proposed rent complies with French rent control for an address' and lists outputs (reference rent, upper ceiling, verdict). It also specifies use cases (max allowed rent, rent cap, is city rent-controlled), effectively distinguishing it from related sibling tools like get_reference_rent.

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?

Provides explicit use cases ('Use for: max allowed rent, rent cap, is a city rent-controlled') that indicate when to select this tool. However, it does not explicitly mention alternative tools or scenarios where a different tool would be more appropriate, such as when only the reference rent is needed.

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