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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description adds the calculation method (sliding scale) and return shape, but says nothing about fee-splitting conventions, caps, or jurisdictional nuances that matter for French agency fees.

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?

Two short sentences, front-loaded with the core action before the cross-reference. The explicit 'Returns: {agency_fees, scale}' duplicates the existing output schema, which is minor waste but otherwise lean.

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?

For a single-parameter, read-only calculator with full schema coverage and an output schema, the description is sufficient: purpose, method, output keys, and a pointer to related tools. Only the French-specific business rules (who pays, standard scale brackets) remain unstated.

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?

With one parameter at 100% schema coverage, the schema already documents 'sale_price' in EUR. The description's 'sliding scale' hints at how the input drives the result but adds no syntax, ranges, or units 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?

States a specific verb+resource ('Calculate French real estate agency fees') plus the method ('sliding scale'), which cleanly separates it from the many fee/tax siblings such as calculate_notary_fees and calculate_property_transfer_tax. There is no explicit contrast drawn against any sibling, but the resource is unambiguous.

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 only routing hint is 'See list_bundles for related immobilier calculators,' which points to bundles rather than describing when this calculator applies versus alternatives. Usage is implied by the name, with no preconditions or exclusions stated.

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