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

With no annotations, the description carries the full burden and does so: it discloses validation behavior, the returned summary/consent line/token, the double-submission requirement, the post-submit email link, and that no provider sees the enquiry until the link is clicked. It also reproduces the exact consent text the person must agree to.

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?

Front-loaded with the most important framing ('NOT a purchase, NOT a guaranteed quote') and ordered step 1/step 2. It is long and the full consent sentence is repeated from the schema, which is minor redundancy, but nearly every sentence carries procedural weight.

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 nested-object, multi-call tool with no output schema, the description supplies the missing return-value semantics (summary, consent line, token) and the full cross-call workflow. Nothing an agent needs to invoke it correctly is absent.

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 coverage is 100%, so baseline is 3, but the description adds genuine meaning: answers are keyed by field key from enquiry_fields, consent is tied to a specific quoted Polish consent string, and confirmation is explicitly the token returned in step 1. It links parameters to the multi-call flow rather than just restating them.

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 and resource ('submits an enquiry'), immediately disambiguates from a purchase or guaranteed quote, and names the provider/domain (Historia Pojazdu VIN). An agent can distinguish this from dataset_* siblings and enquiry_* helpers without opening a schema.

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?

Spells out an explicit two-step protocol: step 1 with answers+consent=true, step 2 with the same answers plus the confirmation token and only after the person agrees. It also points to enquiry_fields for the field keys, giving the agent a clear routing rule.

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