Update Caption

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

Annotations already declare destructiveHint=true and idempotentHint=true, and the description adds a genuinely new trait, the quota cost of 502 units, which is not in any structured field. It also makes explicit that the tool has two distinct effects (file replacement vs. visibility toggle), though it does not say whether a replace is reversible or what happens to an existing track's name/draft state.

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?

Two short sentences: the operation and its two modes are front-loaded, and the quota note follows. Nothing is wasted and nothing is buried.

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?

Output schema and full parameter descriptions exist, and the description covers both operational modes plus cost, which is sufficient for correct invocation. It could state that at least one of file/draft must be supplied, but the remaining gap is minor.

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 parameter including the 100 MB file limit and the my_channel targeting is already documented in the schema. The description's 'show or hide the track' loosely maps to the draft flag but adds no format or syntax detail beyond the schema, 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 and resource ('Replace the file of a caption track') and adds the second mode ('show or hide the track'), which distinguishes it from upload_caption, delete_caption and list_captions. It stops short of naming those siblings, so an agent must infer that this operates on an existing track rather than creating one.

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?

Usage is only implied: 'replace the file' suggests an existing track, and the show/hide clause hints at the draft flag, but there is no explicit when-to-use versus upload_caption (add a new track) or delete_caption. No prerequisites or exclusions are stated.

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