tia_create_unified_hmi_edit_plan

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

Consistent with readOnlyHint=true and adds real behavioral detail beyond it: the plan is exact, dynamic bindings and stale identities are rejected, compile scope hits the entire hosting device, and save is optional with project-wide scope. That scope disclosure is exactly the kind of side-effect context an agent needs and annotations cannot convey.

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?

Three dense sentences with no filler; the read-only plan statement is front-loaded and rejections follow before scope notes. The final sentence's 'Compile covers the entire hosting device' is terse to the point of ambiguity but costs little.

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 plan-generation tool with no output schema, the description covers scope of the plan, rejection conditions, and save semantics. The remaining gap is that it never characterizes the returned plan artifact or how it feeds the companion apply tool, which would complete the picture.

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% across a nested single 'input' object, so the description must compensate. It does partially: 'text in one existing language' maps to language, 'save is optional' maps to saveProject, 'stale identities' hints at processId/processStartTimeUtc, and the property list maps to the geometry/color/font fields. Paths (projectPath, targetPath, screenPath), objectName, and the 8192-range constraints remain unexplained in both places.

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?

States a specific verb and resource: it produces a read-only plan for editing existing Unified HMI control properties (geometry, ARGB colors, localized text, font size). The 'plan' framing usefully separates it from the apply-style siblings without naming them, so the purpose is clear but sibling routing is left implicit.

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?

Usage is implied rather than stated: 'Read-only exact plan' signals this is the preview/plan step before an apply call, and 'Rejects dynamically bound properties and stale identities' gives preconditions. However, it never names the apply counterpart or says explicitly when to skip this tool, leaving the agent to infer the workflow.

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