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

Annotations already cover readOnly, idempotent, openWorld and non-destructive traits. The description adds real value beyond them by stating a privacy boundary — it never identifies the owner or the vehicle's location — and by noting look-alike normalization behavior.

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 tight sentences that front-load the core action and then the constraint. No filler, every clause carries information.

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?

With no output schema, the description usefully indicates the return content (validity plus region). It leaves implicit what an invalid plate yields (error vs. false), but is otherwise adequate for a simple, read-only lookup tool whose annotations cover the safety profile.

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 100%, so the schema documents locale, number, region, and country including examples. The description only restates normalization and region semantics already present in the schema, adding no syntax or format detail beyond it.

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 specific verb+resource (validate a plate number) plus outputs (region lookup), and adds a scope boundary (no owner/location). However, it does not differentiate itself from sibling tools like get_license_plate_country, so an agent may still be unsure which plate tool to pick.

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?

No explicit when-to-use, prerequisites, or alternatives are given. Use is only implied by the verb 'validate', and several sibling tools (get_license_plate_country, get_license_plate_image) leave genuine selection ambiguity unaddressed.

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