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

The annotations already declare readOnlyHint=true and destructiveHint=false, and the description aligns with them by describing the tool as returning a link rather than performing an action. It adds useful behavioral context beyond the annotations: the user, not the agent, performs sign-in, photo upload, cropping, and payment. The explicit warning never to pay or enter card details is valuable safety-relevant disclosure.

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 three sentences with no filler. The core purpose is front-loaded in the first sentence, the trigger is in the second, and the third adds essential user-flow and safety details. Every sentence earns its place and the length is appropriate for a no-parameter tool.

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 no-parameter, read-only tool with no output schema, the description is nearly complete. It tells the agent what the tool returns (a link), when to call it, and what to communicate to the user. A minor gap is that it does not explicitly describe the exact return format of the link or any error/edge-case behavior, but the core invocation context is well covered.

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?

There are zero parameters, so the description does not need to explain parameter meanings. The schema coverage is effectively complete with an empty input schema. The description correctly provides all the information an agent needs to invoke the tool without parameters.

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 action and resource: 'Get the link where the user makes their video.' It clearly distinguishes the tool from the sibling tools by emphasizing that this is about obtaining a link for video creation, not about offers or tips. The second sentence reinforces the intended use case, making the purpose unambiguous.

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 explicitly states when to call the tool: 'Call it once the user wants to make one.' It also gives behavioral guidance about what not to do ('Never pay or enter card details for them'), which helps the agent avoid harmful actions. It does not explicitly contrast with sibling tools, but the trigger condition is clear enough.

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