update_video

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It reveals quota cost (~51 units), explains the read-then-merge-write mechanism, and clarifies that passing only 'title' will not blank the description—a subtle but important side effect. This is transparent and highly useful for an agent deciding how to call the tool safely.

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 compact and front-loaded with purpose. Every sentence earns its place: the first states the action, the second quantifies cost, and the third explains a non-obvious merge behavior. No filler or repetition.

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?

The description covers the essential behaviors—quota, merge semantics, partial update guarantee—and the schema covers required and optional parameters. However, it does not specify what happens when a field is passed as null (clear vs. no-op), nor does it describe the response format, which could matter given there is no output schema.

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%, but the description adds meaningful semantics beyond the raw schema: 'Only the fields you pass change' and the merge example explain how parameter omission behaves. Individual fields are self-explanatory from their names, though the description does not elaborate on each parameter or the meaning of an explicit null value.

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 starts with a specific verb and resource: 'Change the metadata on an existing video.' The phrase 'existing video' clearly distinguishes this from upload_video and other sibling creation tools. It is immediately obvious what the tool operates on and what action it performs.

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 description implies when to use the tool—when you need to update metadata on an existing video without replacing unspecified fields—but it never explicitly names alternatives or states when not to use it. The merge behavior gives contextual guidance, but there is no direct 'use upload_video for new videos' type exclusion.

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