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

The readOnlyHint annotation already declares the safe read-only nature. The description adds value beyond that by specifying return contents: amounts in euros with VAT, platform fees, and tourist tax, plus the filterable dimensions. This gives the agent useful behavioral expectations.

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 concise sentences: the first states the action and optional filters, the second states what is returned. Every word earns its place, with no filler or redundancy.

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 read-only list tool with 3 optional parameters and no output schema, the description fully covers filter semantics and return payload. It mentions the available filters, allowed source values, and the currency plus tax components, which is sufficient for an agent to invoke it correctly.

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 0%, so the description carries the burden. It effectively maps all three parameters: bien (property_id), année (year), and plateforme (source), and enumerates allowed source values (airbnb, booking, abritel, direct, other). This adds meaning beyond the bare 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?

The description uses the specific verb 'Liste' with the resource 'recettes locatives' and immediately clarifies it's a list operation with optional filters. This distinguishes it from siblings like get_income (single item) and list_expenses (different resource).

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 states it lists user rental incomes with optional filters, clearly implying when to use it for collection queries. It doesn't explicitly name alternatives or exclusions, but the context is clear enough for an agent to choose this tool over single-item getters or other list tools.

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