Rate the lighting

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

ReadOnlyHint is true and the description is consistent with that, adding no contradiction. It goes beyond the annotation by disclosing the computation model (inverse-square cosine law, wall shadows, interreflection/split flux) and the standard compared against (ABNT NBR ISO/CIE 8995-1), which tells an agent exactly what to expect from the result.

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 dense but every clause carries relevant information: the physical model, the output format, the reference standard, and the sibling-tool routing. Some jargon (inverse-square cosine, split flux) may be opaque, but it is purposefully concise and not padded.

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 read-only analysis tool with optional parameters, full schema coverage, and an output schema, the description supplies the remaining context an agent needs: what physics is simulated, what metrics are reported, what standard is referenced, and which sibling tools to use instead. Nothing essential is missing.

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 100%: both parameters (room id and work plane height) are already described in the input schema. The description mentions work plane and rooms but adds no new semantic meaning or usage details beyond what the schema provides, so the baseline of 3 is appropriate.

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 identifies this as a lighting evaluation/rating tool: it computes photometric metrics per room and replies with a structured verdict against a reference standard. It distinguishes itself from siblings by describing what fill_lighting does (places fixtures) and where to set a piece's light (place/update light), so an agent can tell them apart.

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 description routes the agent away from this tool when the goal is placing fixtures ('fill_lighting places the fixtures a room needs') or setting a single piece's light ('Set a piece's light with place/update light'). It does not explicitly say 'use this when you need to rate lighting,' but the title and output description make that context clear.

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