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

Beyond the readOnlyHint annotation, the description adds non-obvious behavioral details: it refuses to return projections ('those ratios change constantly...'), defines budget constraints ('minimum 200000, invoiced in full'), and notes the API key requirement. No contradictions with 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 four sentences, front-loaded with the main purpose, and every sentence adds essential context: the exact output fields, the intentional omission of projections, the budget rule, the example, and the auth requirement. No 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 one-parameter read-only tool with an output schema, the description covers all necessary operational knowledge: input language support, output fields, special behavioral constraints, example input, and authentication. Sibling context and annotations round out the picture.

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 already describes the single parameter 'brief' with 100% coverage, so the baseline is 3. The description adds a concrete example and restates language support, but this is marginal over the schema description.

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 states a specific action ('Structures a free-text campaign brief...') with a clear resource and scope. It distinguishes itself from sibling tools by explicitly saying 'Writes nothing' and 'Returns NO projection of views...', separating it from creation or status-checking tools.

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 gives clear context: use when you have a free-text brief in French or English and want structured campaign fields. It implicitly differentiates from create/order tools via 'Writes nothing', but does not explicitly name alternatives or exclusions, so it stops short of a 5.

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