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

Annotations already declare readOnlyHint=true, so the agent knows this is a safe read. The description adds useful context about the response contents (amounts, fees, taxes, reservation info), but it does not disclose potential error behaviors, authorization requirements, or any constraints beyond the read-only hint. This is comparable to the get_calls calibration example, achieving a baseline of 3.

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 a single, dense sentence that front-loads the verb ('Retourne') and resource ('détail complet'), then efficiently enumerates the key data fields. No words are wasted, and all information is relevant. It is concise yet comprehensive enough.

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?

The tool is simple: one parameter, read-only, with no output schema. The description effectively fills the gap by listing the expected return fields. It informs the agent what data will be available. It could mention the single-object nature or distinguish from list_incomes, but the description is complete enough for an agent to decide when to use this 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?

The schema has one parameter, income_id, with no description (0% schema coverage). The description compensates by stating 'par son identifiant' (by its identifier), directly linking income_id to the rental income being fetched. The parameter name itself is self-explanatory, and the description reinforces its purpose. Given the low schema coverage, this added clarity is valuable, leading to a score above baseline.

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 clearly states the tool's function: 'Retourne le détail complet d'une recette locative par son identifiant' (returns complete rental income detail by ID). It lists the specific data returned (TTC/HT, TVA, fees, etc.), which distinguishes it from sibling tools like list_incomes (which likely lists all) and create_income/update_income/delete_income.

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 when you have a specific income identifier and need full details. It does not explicitly name alternatives or exclusions, but the 'par son identifiant' makes the context clear. Since this is a standard get-by-ID pattern, the absence of explicit alternative guidance is acceptable, though mentioning 'use list_incomes for overview' would be stronger.

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