youtube_update_video

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

With no annotations, the description carries the burden of behavioral disclosure. It reveals key traits: partial updates, max lengths for title/description, and that tags fully replace existing tags. These go beyond the basic 'update' action and give an agent a clear model of the tool's side effects, though it omits auth requirements and error behavior.

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 description is concise and well-organized: a clear purpose sentence, a key behavioral note, and a tidy Args list. Every sentence and list item earns its place without redundant filler, making it highly scannable for an agent.

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 6-parameter update tool with no output schema and no annotations, the description covers the essential aspects: partial update behavior, parameter constraints, and replacement semantics. It falls slightly short of a 5 by not mentioning output/return behavior or auth prerequisites, but it is sufficiently complete for a straightforward metadata update.

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 0%, so the description must compensate. It does so thoroughly: it adds max character limits for title and description, explains that tags replace existing tags, and enumerates valid privacy_status values. This adds significant meaning beyond the bare schema property names.

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 'Update metadata for an existing video,' a specific verb+resource that clearly distinguishes this tool from siblings like youtube_upload_video, youtube_delete_video, and youtube_set_thumbnail. It also clarifies partial-update semantics, making the tool's purpose unmistakable.

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?

The statement 'Only provided fields are updated; others remain unchanged' gives useful guidance on how to use the tool for partial updates. While it does not explicitly list alternatives, the phrase 'existing video' implicitly differentiates it from upload and other mutation tools, providing enough context for an agent to choose appropriately.

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