getCaptions

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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds genuine interpretive context beyond that: the meaning of resolvedLane (recording speech vs voiceover tracks), that language null means the transcript's own words, and that 'warning' fires when captions are on with nothing to show.

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 content is front-loaded with 'Read the captions,' but it is delivered as one very long, dense run-on sentence enumerating many properties. Since there is no output schema, the detail earns its place, but the structure would be more readable if broken into grouped points.

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 carries the burden of describing return values and does so thoroughly: style, position, lane, language, captionedAssets, warning, translations and choices. For a simple read-only tool this is essentially complete, with the only gap being explicit routing guidance to siblings.

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 the single projectId parameter is already fully documented in the schema, including the note about omitting it for the editor-open project. The description text adds nothing further about the parameter, so the baseline 3 applies.

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 clear read operation on a specific resource (caption display configuration) and enumerates exactly what is returned: enabled state, style, positioning, lane, language. It is unambiguous what the tool does, though it never names a sibling alternative (e.g. setCaptionSettings for writes), so sibling differentiation is only 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?

There is no explicit guidance on when to use this tool versus alternatives such as getCaptionTranslationUnits or getTranscript. It mentions that 'choices lists what setCaptionSettings accepts,' which hints at a write counterpart, but gives no condition for choosing getCaptions or when not to call it.

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