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

Beyond the annotations (readOnlyHint=false, openWorldHint=true, non-idempotent), it discloses the key async trait: generation takes minutes, the call only kicks off a job, returns a jobId, and requires polling. That is exactly the behavior an agent cannot infer from annotations. It does not cover failure modes, credit costs, or cancelability.

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 front-loaded purpose is good, but the body is a run-on with inconsistent line breaks, an awkward conditional clause, and a trailing colon leading to an empty list. The empty enumeration is dead weight that leaves the reader expecting content that never arrives.

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 3-required-parameter tool with 0% schema coverage, the description leaves the entire input contract unexplained; the one attempt to document the video types is an empty list. The async/jobId workflow and the surrounding sibling choreography are well covered, but an agent still cannot construct the arguments from this text.

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% across three required parameters, and the description says nothing about 'identifier', the vertical/horizontal 'output' enum, or which keys belong in 'customParams'. The dangling 'Here are the type of video that can be generated:' colon looks like it was meant to enumerate customParams values but the list is empty, so no meaning is added.

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 states a specific verb+resource ('Generate video to use in a post') and implicitly separates it from generateImageTool by discussing an attachment-driven workflow. It gets muddied by the confusing phrase 'ask if they want to generate a picture of a video', which blurs whether this tool makes videos or images.

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 names the trigger condition (a platform requires an attachment that wasn't provided), a prerequisite sibling ('videoFunctionTool' for things like voice id), and the follow-up sibling ('videoStatusTool' polling until 'completed'). There are no explicit when-not-to-use rules, and the 'picture of a video' sentence introduces ambiguity about the alternative.

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