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 only 'Returns total points and mention,' which is already carried by the output schema, leaving little behavioral value beyond structured data. No auth, precision, or edge-case disclosure.

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?

Three front-loaded sentences, with the core purpose first and no filler. The trailing list_bundles pointer is slightly tangential but does not bloat the text meaningfully.

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 an output schema present, the description needn't explain return values, and annotations cover the safety profile. It is complete enough for its target audience, with only the missing sibling/alternative routing as a gap.

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 six parameters with ranges (e.g., socle_commun 50-400, science /50). The description's 'grades by subject, continuous control' is a loose restatement rather than added meaning, so baseline 3 applies.

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: 'Estimate French Brevet (DNB) score from grades and continuous-control marks.' The 'Brevet (DNB)' framing distinguishes it from the nearby calculate_bac_points sibling, though the differentiation is implicit rather than stated. Clear purpose with mild sibling ambiguity.

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?

'Use for collège students forecasting their result' gives the target audience/context but no when-not guidance and does not name calculate_bac_points as the alternative for lycée students. The 'See list_bundles' pointer is a cross-reference to a discovery tool rather than an alternatives guide, so usage is implied rather than explicit.

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