control_plc

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

Annotations already declare openWorldHint=true and destructiveHint=true, so the agent knows the tool reaches out and can cause destructive effects. The description adds a genuine behavioral detail beyond that — a preflight ping of the target PLC before start/stop — but says nothing about the consequences or reversibility of halting a running PLC, which is the most decision-relevant side effect.

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 tight sentences with the action set front-loaded and the preflight ping follow-up. Nothing is padded and no sentence is wasted.

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?

With no output schema, the description should say more about what get_state returns and what the ping/start/stop operations produce on failure. It covers purpose and one side effect adequately, and annotations carry the safety profile, but a destructive multi-action control tool warrants more detail than is present.

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 description coverage is 100%, so action, lcp_path, and connection are fully documented in the schema including the enum semantics and the 'omit to use default' behavior. The description adds no syntax, format, or interaction detail beyond what the schema already provides, making baseline 3 correct.

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 names a specific verb set (start, stop, query) and the exact resource (PLC runtime state), so the agent knows this is the control tool rather than a read-only one. It does not, however, distinguish itself from siblings like lasal_status or lars_runtime, which may also surface runtime state, leaving some ambiguity in a crowded toolset.

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?

There is no statement of when to prefer this over lasal_status, plc_diagnostics, or lars_runtime, nor any exclusion or prerequisite guidance. The only guidance is the implicit mapping of the three actions, which the schema already conveys.

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