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

Annotations already declare readOnlyHint, idempotentHint, non-destructive, and closed-world behavior, so the safety profile is covered. The description adds the French-jurisdiction context and lists return fields, but does not disclose calculation assumptions, legal disclaimers, or rate-determination logic. It adds some value but not rich behavioral context beyond the annotations.

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 two sentences, front-loads the core purpose, and avoids waste. The return-field sentence duplicates the output schema, but the overall structure is efficient and easy to scan.

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 low-complexity calculator with full schema coverage, annotations, and an output schema, the description gives enough context to select and invoke it: domain, inputs, and output shape. It could be stronger by noting that results are estimates rather than legal advice or by clarifying the bundle reference, but no critical invocation detail 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 description coverage is 100%, so the schema already fully documents income, custody, and children_count, including the custody enum and defaults. The description names the same inputs but adds no syntax, formatting, or constraint detail beyond what the schema provides. Baseline 3 is appropriate when the schema does the heavy lifting.

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 uses a specific verb ('Estimate') and resource ('French child support (pension alimentaire)'), and names the three input factors. It clearly distinguishes this calculator from the many generic siblings by specifying French child support rather than a generic financial or tax calculation.

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 usage by stating the domain and inputs, but gives no explicit when-to-use or when-not-to-use guidance. The only routing hint is 'See list_bundles for related finance-france calculators,' which points to a bundle browser rather than explaining when to choose this tool over alternatives.

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