Update Captions

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

Annotations already flag destructive=true, idempotent=false, openWorld=true, but the description goes further by naming the required token scopes, the delegation scope option, the confirm=true gate, and the warning that the call 'may share access, notify people or incur provider charges.' That extends well beyond the structured safety hints.

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?

Purpose is front-loaded in one sentence, followed by scoped permission and side-effect blocks. The code-fenced permission text is somewhat bulky, but each section carries distinct operational value.

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, non-idempotent mutation with no output schema, the definition covers purpose, auth requirements, the confirm gate, and side-effect risk. There is no output schema to explain return values, and the schema fully documents the seven parameters.

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 media_hashed_id, language_code (ISO-639-2), caption_file format, account, and confirm are all documented in the schema itself. The description adds nothing about parameter format or interaction (e.g., payload vs caption_file vs payload_file exclusivity), so 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?

States a specific verb ('replacing the captions') and resource scope (video/audio media, specified language), so the agent knows this is an overwrite rather than an append. It does not, however, distinguish itself from siblings like edit_captions_text or create_captions, leaving the boundary between 'update' and 'edit' unclear.

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 auth prerequisites and the confirm=true requirement, which is real operational guidance. But it never says when to choose this over edit_captions_text, create_captions, or delete_captions, nor what happens if captions for the language don't already exist.

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