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

With annotations already declaring the safety profile (readOnlyHint=false, destructiveHint=false, non-idempotent), the description adds genuinely useful behavior: the URL must be publicly reachable, the media is stored as provided without copying, and human approval is required before publish. It doesn't address retry/idempotency semantics, but the added context is substantive.

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?

Purpose is front-loaded and the sentences are dense with no filler; the semicolon cleanly attaches the upload alternative to the core purpose. Slightly longer than strictly necessary given the approval-workflow sentence could be trimmed, but nothing is wasted.

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 mutation tool with 16 params and no output schema, the description covers purpose, the upload alternative, storage semantics, and the approval gate, leaving field-level detail to the schema. It omits what a successful call returns (draft/video id) and any failure behavior, which would help an agent chain into publish/schedule.

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 coverage is 81%, so the schema already documents the URL parameters, aliases, and most fields. The description reinforces the public-URL requirement and 'stored as provided' behavior but adds little that the schema text ('Publicly accessible HTTP(S) video URL') doesn't already say, and it ignores the required contentGroupId and the many optional targeting params.

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 gives a specific verb and resource ('Create a video draft from a video URL') plus a scope qualifier ('already publicly accessible') that separates it from generateVideo (which synthesizes media) and from the upload path. An agent can identify the tool without opening the schema.

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 explicitly names the alternative and the condition that selects it: 'for a file the user has, call createUploadLink first.' It also states a workflow precondition (get user approval of destination and timing before scheduling/publishing). It stops short of naming scheduleVideo/publishVideo as the follow-on tools, so the routing is clear but not fully spelled out.

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