hmi_vs_runtime

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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds real behavioral context beyond that: it discloses exactly what categories of mismatch are reported (broken bindings vs orphan declared variables) and that check_source extends the analysis to source declarations. It stops short of describing output shape, but an output schema exists.

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?

A single sentence, front-loaded with the key concept ('Broken HMI bindings'), with no filler. The parenthetical and comma-plus clause make it dense and slightly awkward to parse, but the compactness is appropriate and every clause carries information.

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 explained, and the safety profile is in annotations. What's missing is disambiguation from the many HMI/PLC-comparison siblings and any guidance on preconditions or scope, leaving the definition adequate but with clear gaps for a heavily populated sibling set.

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 0%, so the description must carry the burden for the single boolean parameter. The parenthetical '(and, with check_source, whether the source declares them)' gives a partial semantics hint for check_source, but it doesn't clarify the default-on behavior or the cost/tradeoff of enabling it. Partial compensation only.

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 states a specific diagnostic purpose: identifying HMI-bound symbols that don't exist on the running PLC plus declared variables with no HMI. It is concrete about what it reports. However, it does not distinguish itself from close siblings like hmi_bindings, hmi_scan, or proj_vs_runtime, leaving the agent to guess which to use.

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 when-to-use guidance and no alternative tool is named or excluded. The only usage hint is the parenthetical describing what check_source adds, which is a parameter note rather than usage context. An agent cannot tell from this description when to prefer this over hmi_bindings.

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