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

Annotations already declare non-read-only, non-idempotent, non-destructive, closed-world behavior, so the description need not repeat that. It does add one genuinely useful behavioral fact beyond annotations: omitting the odometer reuses the last known reading. It says nothing about duplicate handling (relevant given idempotentHint=false) or what happens if the vehicle cannot be resolved.

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?

A single front-loaded sentence with zero filler; the core action comes first and the odometer fallback follows. The embedded example is short and clarifying rather than padding.

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 four-parameter create-style tool with full schema coverage and annotations covering the safety profile, the description plus structured fields are largely sufficient. Minor gaps remain around vehicleId vs vehicleName resolution and failure behavior for an unknown vehicle.

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 all four parameters are documented in the schema, including the kmValue fallback which the description merely restates. The description adds no precedence rule between vehicleId and vehicleName, which is the one ambiguity the schema leaves open.

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: logging a note/issue against a fleet vehicle plus an odometer reading, with an example ("brakes squeaking") that pins down intent. It is distinguishable from generic siblings like saveNote by the fleet-vehicle and odometer framing, though it never explicitly contrasts itself with them.

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?

Usage is implied by the fleet-vehicle + odometer framing, and one conditional rule is given (omit kmValue to reuse the last known reading). There is no explicit when-to-use/when-not-to-use guidance and no named alternative such as saveNote for non-vehicle notes.

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