Update Captions

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

Annotations already cover the safety profile (destructiveHint=true, idempotentHint=false, openWorldHint=true), and the description adds real value on top: the required scope, the delegated-permission variant, the mandatory confirm=true, and the warning that the call may share access, notify people, or incur provider charges. That is meaningful side-effect disclosure beyond structured fields. It stops short of saying whether other languages' captions are preserved.

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 core purpose sentence is front-loaded and the permission notes are block-quoted and skimmable. It is somewhat verbose in the authorization section, but each element (permissions, delegation, confirm, side effects) carries distinct operational 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?

For a destructive, 7-parameter mutation with no output schema, the description covers authorization, the confirm gate, and side effects well. The remaining gap is the effect on existing caption data and localization variants, which an agent would want before overwriting captions.

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 every one of the seven parameters is documented in the schema itself. The description adds no parameter-level detail (e.g., SRT content handling or ISO-639-2 format) beyond what the schema states, 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?

States a specific verb and resource with scope ('replacing the captions on a video or audio media for the specified language'), so an agent knows exactly what operation this performs. It does not, however, distinguish itself from close siblings such as edit_captions_text or create_captions, which an agent would need in order to choose correctly.

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?

Provides the precondition that confirm=true is required for the mutation and documents the permission scopes needed, which is useful routing context. But it never says when to use this tool instead of edit_captions_text, create_captions or delete_captions, so the when/when-not decision is left to inference.

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