Get Charging Status

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

Beyond the readOnly and idempotent hints, the description discloses meaningful behavior: 5-minute caching, partial/case-insensitive name resolution, the returned vin/name being resolved from that lookup, and the semantic difference between 'no vehicle matched' and 'server_unavailable' errors. This gives an agent a solid model of side effects and edge cases.

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?

The description is dense but every sentence contributes: the return field list, the resolution behavior, the two error modes, and caching. It is front-loaded with the core purpose and then layers details in a logical order with 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 single-parameter read-only tool with an output schema, the description covers what is returned, how to provide vehicle_id, how errors are surfaced, and the caching behavior. Nothing an agent needs to decide whether to call or how to interpret the result is missing.

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?

The schema already fully documents vehicle_id with 100% coverage, so the baseline is 3. The description adds extra semantics: it explicitly says matching is partial and case-insensitive, and that the resolved VIN/name will be included in the response. That is value beyond the schema.

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 opens with a specific verb and resource — 'Get charging/plug status for an electric vehicle' — and enumerates the exact returned fields (is_charging, charging_state, plug-connected flag, target/current SoC, range, timestamp, resolved VIN/name). This clearly distinguishes it from siblings like get_vehicles and get_vehicle_info, which are about listing vehicles or general info, not charging state.

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 tool's intended use is clear from the description: you call it whenever you need an EV's charging status. It also provides practical guidance like partial case-insensitive name matching and what each error shape means. It doesn't explicitly mention when to prefer get_vehicle_info instead, but the focused domain makes the appropriate context obvious.

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