Plc Browse

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

The description adds behavioral details beyond the annotations: it explains the return structure ({node, children, total, shown, truncated}), the output budget (max 200 children, ~30KB), truncation behavior, default starting node, and the need to call again with a child node_id for deeper levels. It also notes the protocol limitation. No contradiction with the readOnlyHint.

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 a single, dense paragraph that front-loads the core function and return format. It is efficient, but slightly long; however, every sentence adds value, covering purpose, usage, and behavioral constraints.

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?

The description covers the essential aspects: return structure, truncation behavior, default node, usage context, protocol limitation, and output budget. The output schema likely defines the return format, so the description focuses on behavior. It could detail more parameters, but overall it is complete enough for the tool's scope.

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 0%, so the description must compensate. It explains the 'node' parameter (default ns=0;i=85) and 'limit' (output budget of 200), and implies 'protocol' by restricting to OPC UA. However, it does not describe host, port, unit, or timeout_ms, leaving these to be inferred from context.

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 tool's purpose: browse the address space by expanding one level of child nodes from a given node, framed as a 'list directory' for diagnostics. It differentiates from siblings like plc_read (reading values) and list_protocols (listing protocols) by specifying when to use it and what it returns.

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 explicitly says to use this before plc_read to understand the address space structure, and notes that it only supports OPC UA, directing users of other protocols to use list_protocols' read_options instead. This gives clear when-to-use and when-not-to-use guidance.

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