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

Annotations are all false, so the description carries the burden of behavioral disclosure. It adds useful context: the call is project-scoped, returns the project identity with the result, and cannot add resolution. However, it does not disclose whether the operation is asynchronous (e.g., requiring wait_for_job), side effects on existing media, or reversibility. Given the mutation nature (readOnlyHint=false), more disclosure would be beneficial.

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 dense and front-loads the critical scope and purpose. It is a single block but effectively organized: scope, purpose, parameter details, and limitations. No wasted sentences, though the lack of formatting makes it slightly harder to parse.

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 5-parameter tool with no output schema, it covers the essential usage, parameter semantics, and key limitations. The main gap is the absence of information about asynchronous behavior or the exact shape of the result beyond 'project identity with its result'. This is a minor omission given the overall richness.

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?

With only 20% schema coverage, the description compensates fully. It explains sharpen (0-1, default 0.5, purpose), denoise (0-1, default 0, purpose and ordering relative to sharpen), and start/end (program seconds, omit both for whole video). project_id is already described in the schema. All parameters gain meaning beyond the raw schema.

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 clearly states the tool's function: enhancing picture quality via sharpening and denoising. It explicitly distinguishes itself from look-based tools ('PICTURE QUALITY, not a look') and names the exact user intents it addresses ('make it clearer / sharper / better quality / HD / enhance this'). It also states it is project-scoped, which is a precise scope.

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 provides explicit when-to-use guidance by mapping to user phrases and warns against using it for resolution increases or colour grading. It also gives operational advice like raising denoise before sharpen on noisy footage. It does not name specific sibling tools as alternatives, but the differentiation is clear enough for an agent to select it.

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