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

Annotations already declare readOnly, idempotent, and non-destructive, so the safety profile is covered. The description adds genuinely new behavior: results are based on a cached location (potentially stale or not the car's current position) and the call avoids waking the vehicle. That is real value beyond the structured fields.

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 short sentences, front-loaded with what the tool returns before the caveat. No filler or 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 simple read tool with no output schema, the behavioral picture is adequate and the cached-location caveat is valuable. But with two undocumented parameters at 0% schema coverage, the definition leaves the agent without enough to call it correctly.

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 0% and the description makes no mention of either parameter. It never explains that 'vin' selects the vehicle or what 'limit' constrains (count of results), so the agent must guess at both.

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 ('Returns nearby Superchargers') plus a scope qualifier ('from the last cached location'), so an agent knows exactly what it gets back. It is distinguishable from siblings like get_charging_status or get_location, though it never names 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?

The line 'Does not wake the car' implicitly tells the agent this is the non-intrusive option versus wake_vehicle, which is useful routing. However, there is no explicit when-to-use/when-not statement and no named alternative, so guidance remains inferred.

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