plc_find_references

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

Annotations already declare readOnly, idempotent, non-destructive, closed-world behavior, so the description is not needed for the safety profile. It still adds real behavioral value by disclosing that matches are purely textual (comments and strings excluded) and that scope and external HMI dependencies are not resolved — this tells the agent results will be incomplete in ways that matter for correctness.

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 compact sentences with zero filler; the positive scope statement comes first and the limitation follows. Nothing needs to be trimmed and nothing is buried.

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?

An output schema exists, so return values need not be described, and the tool's operation is conceptually simple. However, the two undocumented parameters (symbol format especially) and the absence of any positive when-to-use condition leave meaningful gaps for an agent trying to invoke 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 coverage is only 50%: limit and offset are documented in the schema, but 'symbol' and 'project_id' have no description anywhere. The description says nothing about parameter meaning — not whether symbol must be a fully qualified path, how partial or case-sensitive matching works, or how limit/offset interact with the lexical result set. It does not compensate for the coverage gap.

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 uses a concrete verb and resource ('Find lexical ST/LD references') and narrows scope with 'lexical' plus the comment/string exclusion, so an agent can tell it apart from a semantic analyzer like plc_analyze_symbol. It does not explicitly name a sibling alternative, which keeps it below a 5.

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 resolve scope or external HMI dependencies' implies when this tool is insufficient and that another capability is needed for semantic resolution, but it never states the positive condition for choosing this tool or names the alternative to use instead. Usage is therefore implied rather than prescribed.

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