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

Adds substantial context beyond the readOnly/openWorld annotations: cost (10 credits per call), DVF data coverage window (2014–2025, annual cadence), and a reliability caveat (use ≥12 month windows). These are exactly the operational facts an agent needs before committing a paid call.

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 purpose, then uses labeled sections (REQUIRED / Optional / Returns / Example / Note / Cost) so an agent can scan quickly. Two examples and the Returns block are slightly redundant but each carries distinct information.

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?

With no output schema, the description compensates by enumerating the per-location return fields (transaction count, median price/m², YoY change, rankings). Combined with the cost, data-range, and default notes, nothing needed to call or interpret the tool is missing.

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 already 100%, so the baseline is 3; the description goes further by clarifying that each location object takes either {code_postal} or {commune}, restating the defaults, and showing two worked invocation examples that illustrate the alternative shapes.

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 (compare), resource (2-5 neighborhoods/locations), and scope (side-by-side, 2-5) in the first line. The 'investment location decisions' framing distinguishes it from single-location siblings like analyze_market_statistics or estimate_property_value.

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?

Gives a clear use case ('perfect for investment location decisions') and concrete invocation examples for both code_postal and commune forms. It does not, however, name alternatives or state when not to use it versus e.g. find_property_comparables.

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