Translate title and description

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

Annotations already declare idempotentHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is covered. The description usefully adds the merge semantics and the default_language prerequisite, which are behaviors the annotations do not convey. It says nothing about what happens on conflicting titles, on invalid language codes, or what the call returns, so the added value is real but partial.

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?

Three short sentences, front-loaded with the action and immediately followed by a concrete payload example, then the merge behavior and the prerequisite. Every sentence carries information; the one weak spot is that the example inline with the first sentence slightly interrupts the purpose statement.

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 nested-object mutation with no output schema and only 25% schema description coverage, the description covers the payload structure and the key precondition well. It leaves the remove_languages parameter and the response behavior unexplained, which an agent needs in order to use the full surface of this tool correctly.

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 only 25%: channel is documented, while video_id, localizations and remove_languages are bare. The description compensates well for localizations by giving the exact shape and a concrete example keyed by language code, and it flags the default_language precondition. However, remove_languages receives no explanation at all despite being a distinct mutation path, leaving a meaningful gap the schema does not fill.

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 opens with a specific verb pair ('Add or update') and a specific resource ('the title and description shown to viewers in other languages'), and names update_video as the related sibling for setting default_language. It is clearly distinct from update_video and the caption tools, though it never states the canonical term 'localizations' that the parameter uses.

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?

It gives real preconditions: the video must already have default_language set, and that is done via update_video. It also states that new entries are merged with existing translations rather than replacing them. It stops short of naming when-not-to-use cases or an alternative for removing translations, so it is clear context but not a full routing rule.

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