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

Annotations already declare readOnlyHint=false, idempotentHint=false and openWorldHint=true. The description adds real behavioral context beyond that: the response returns an `upload_url` and a PUT request is required to actually transfer the file, plus the `input` parameter is rejected. It does not mention auth/permission requirements or what happens to an abandoned upload.

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?

Three front-loaded sentences: purpose, the parameter-divergence caveat, then the response/next-step contract with a docs link. No filler and the critical next step (PUT to upload_url) is stated before the reference link.

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 26-parameter, zero-required mutation tool with an output schema present, the description supplies the missing two-step upload contract that the schema cannot express, and the output schema covers the return shape. It stops short of permissions, failure handling, or upload URL expiry, which would round it out.

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 the baseline is 3. The description adds one genuinely useful semantic note: all body parameters mirror Create Asset except `input`, which this endpoint omits. That is modest but real added meaning over the schema, which cannot express the cross-tool relationship.

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?

States a specific verb and resource ('creates a video asset allowing upload ... from the local file system') and pins down the workflow with the create-then-PUT upload_url sequence. It also implicitly distinguishes itself from create_asset by noting the one body parameter (`input`) it does not accept.

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 usage through the local-file-system upload flow, but never states explicitly when to choose this over create_asset or complete_multipart_upload, nor any prerequisites. It points to external docs for the upload step, which partially compensates but leaves selection guidance to inference.

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