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

Beyond the annotations (readOnly/idempotent/non-destructive/openWorld=false), the description discloses the actual runtime behavior an agent cannot infer: the call returns covered:false and an official Safety Gate URL, i.e. it is a deliberate no-op placeholder. That is genuinely useful and consistent with the annotations; no auth, rate-limit or side-effect detail is needed for a stub.

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?

Two sentences, front-loaded with 'STUB — not yet live', which is the single most decision-relevant fact, followed immediately by the alternative. No filler.

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 stub with no output schema, the description covers the essentials: it is not live, what it returns, and where to go instead. The remaining gap is the unaddressed brand/model parameters and any hint of when the stub will become live, but for a placeholder this is close to complete.

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?

Both brand and model are undocumented in the schema (0% coverage) and the description never mentions them, so an agent gets no signal whether they filter, are ignored, or are reserved for the live version. The stub framing mitigates this slightly, but the description does not compensate for the coverage gap as required.

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 exactly what the tool currently is and does: a not-yet-live stub for EU Safety Gate (RAPEX) vehicle alerts that returns covered:false plus the official URL. It names the resource precisely and distinguishes itself from siblings by naming fr_recalls_*. It stops short of 5 only because the eventual retrieval behavior is described prospectively ('are being added') rather than fully defined.

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?

It gives explicit when-not guidance ('not yet live') and routes the agent to an alternative family (fr_recalls_*) with the reason that RappelConso republishes the Safety Gate automobile alerts concerning France. The routing is conditional on the agent needing the data rather than a blanket 'always use X', which keeps it just under a 5.

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