read_dtc

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

The description discloses that the tool does not modify the ECU, which is a key behavioral trait for a read operation. It also mentions that technical descriptions are included when known, adding some context beyond the name. However, it does not mention connection requirements, error behavior, or any other side effects, and since annotations are absent, the description carries the full burden.

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 two concise sentences, front-loaded with the primary purpose. Every word adds value, and there is no 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 zero-parameter tool with an output schema, the description covers the essential information: what it reads, that it includes descriptions, and that it's non-destructive. The only gap is usage guidance, which is captured separately. Overall, it's adequate for the agent to call the tool 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?

The tool has zero parameters, so the description has nothing to add about parameter semantics. The schema coverage is trivially 100%, and the baseline for zero-parameter tools is 4, which is appropriate.

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 clearly states the verb (read) and resource (diagnostic trouble codes), and specifies the scope (stored and pending/current-cycle). It does not explicitly name sibling tools, but the purpose is unambiguous and distinct from clearing codes or reading sensors.

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 guidance is given on when to use this tool versus alternatives. The description does not mention that clear_dtc is for erasing codes or that read_sensor is for live data, so the agent must infer the appropriate context from the name alone.

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