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

The description adds substantial behavioral context beyond annotations: it drives a real browser, is slower than generation, returns a job_id for polling, and returns a clean error for 4K plan locks. It also discloses the return payload, which is valuable since no output schema exists. No contradiction with annotations.

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 organized into clear thematic paragraphs: purpose, account semantics, resolution options, performance/polling behavior, and return value. Every sentence adds necessary operational detail without redundant filler.

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?

Given the tool's complexity, lack of output schema, and 0% schema coverage, the description is remarkably complete. It covers what, from where, with which account, resolution choices, failure mode, latency behavior, polling approach, and the full return shape. Nothing critical is missing.

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 carry the parameter meaning. It fully explains media_id (prior generated video scoped to an account), account (must match the farm account owning the media), and target_resolution ('1080p' or '4K', with the caveat about paid plan locking). Every parameter is meaningfully documented.

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-resource pair: upscaling an existing generated video to a higher resolution. It clearly scopes the input to prior generate_video output and distinguishes this from image upscaling and other generation tools.

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 explicit prerequisites: reuse the farm account whose project owns media_id. It also tells the agent how to handle a 4K plan-lock error, and directs polling check_job when the job exceeds ~40s. This is actionable usage guidance with error-handling behavior.

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