measure_frame_color

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

With no annotations, the description carries the burden; it does disclose the return values (luma and R/G, B/G ratios) despite there being no output schema, which is valuable. However, 'Exports a sequence frame' is an undisclosed side effect — it does not say where the frame goes, whether files are written or cleaned up, or whether the operation is read-only with respect to the project.

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 front-loaded sentence with no filler; the verb and the returns come first. The trailing parenthetical '(or a given region / midtones)' is slightly compressed but does add a real qualifier rather than padding.

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?

It covers what is measured and what comes back, which is important given no output schema. But for a tool with 4 parameters, no annotations, and an implied frame export, an agent is still missing prerequisites (target sequence context), the effect of exporting, and the meaning of the undocumented 'time' parameter.

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 75%, so the baseline is 3. The parenthetical '(or a given region / midtones)' reinforces the schema's region description and confirms the fallback behavior, but the description adds nothing about 'time' (unspecified in both schema and description) or about the sequenceId/sequenceName choice.

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 action pair (export a sequence frame, then measure it) and names the exact outputs (luma Y, R/G and B/G ratios). It is distinguishable from siblings like capture_frame or export_frame because it returns measurements rather than files, though it never names those siblings explicitly.

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?

No when-to-use or when-not-to-use guidance. An agent cannot tell from the description whether this should be preferred over match_color, compare_frames, get_lumetri_basic, or capture_frame for color analysis, nor whether the sequence must be open or active first.

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