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

Behavioral disclosure is unusually strong: the tool is asynchronous, returns a job id immediately, takes one to a few minutes to render, is billed per second of video, charges when rendering starts, and refunds in full on failure. It also matches the POST /videos endpoint semantics, which helps the agent understand the side effects.

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 front-loaded with purpose and next step, then pricing and defaults. It is a bit long, and the Persian sentence repeats the English async/polling instruction, but every part remains relevant to correct invocation.

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?

There is no output schema, yet the description fully covers the return contract: a job id, asynchronous rendering, and polling via get_video. For a non-destructive async creation tool, no essential agent-facing behavior 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 100%, so each of the four parameters is already documented in the input schema. The description adds only the default model and shortest-length default, which are useful but largely duplicate schema-provided defaults.

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 uses a specific verb and resource — 'Start rendering a short video from a text description' — and distinguishes the tool from the sibling get_video by framing it as the job starter. An agent can immediately tell this is the video-creation entry point, not a status or image tool.

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 clearly tells the agent to poll get_video with the returned id until status is 'completed', which is the key usage flow. It also supplies the default model and default shortest length. It does not explicitly exclude related tools like generate_image, but the 'short video' scope is clear enough.

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