gx3_xref_where_used

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

No annotations are provided, so the description carries the burden. It discloses the xref DB prerequisite and implies a read-only lookup, but it does not describe the output shape, failure behavior if the DB is missing, or any other side effects beyond the query nature.

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 sentences, front-loaded with the core purpose and followed by the essential setup command. Every sentence adds value with no redundancy or 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 two-parameter lookup with no output schema, the description gives enough to select and invoke: the return type, the input requirement, and the prerequisite setup. The phrase 'POU name and real step' is somewhat ambiguous but is likely domain-specific, and the schema covers the parameters, making this adequate for the tool's complexity.

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 input schema already covers both parameters (`root` and `device`) fully at 100% coverage. The description adds no parameter-level detail beyond what the schema provides, so the baseline score of 3 applies.

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 identifies the tool's output as 'Writers and readers of a device', indicating this is a where-used query. It is clear about the resource (device) and the kind of result (writers and readers), though the verb is implicit and it does not explicitly distinguish itself from siblings like gx3_trace_device.

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?

It provides a concrete prerequisite ('run gx3-cli xref build --root <root> once per project first'), which is important usage context. However, it does not explicitly state when to prefer this tool over alternatives or mention any exclusions.

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