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

Adds genuinely non-obvious behavior beyond the annotations: the tool 'opens nothing by itself' and only returns procedural guidance, so the agent knows no Midjourney state is touched and follow-up browser calls are required. The extra note that Midjourney has no public API pre-empts an incorrect assumption. Missing only detail on what the returned guide looks like in practice.

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?

Front-loads the core action and the critical 'returns how to do it, opens nothing' qualifier in the first two clauses. The semicolon-chained structure and trailing API footnote make it denser than necessary, but no sentence 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 zero-parameter, read-only guidance tool, an agent has enough to call it and knows what to do with the result. A short note on whether the returned steps depend on the user's plan or current Midjourney UI state would have closed the remaining gap.

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?

The schema has zero parameters, so there is nothing for the description to disambiguate; baseline applies. The description correctly signals a no-argument call by describing a fixed informational response.

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?

Names a specific verb and resource (extend video, Midjourney) and immediately clarifies the real function: it returns step-by-step instructions rather than performing the extension. It stops short of distinguishing itself from nearby siblings like midjourney_animate_image, so a 4 rather than a 5.

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?

Supplies a clear workflow: call this first to get the Midjourney screens/buttons/fields, then execute with the cotlet_browser_* tools. It does not state explicit exclusions or prerequisites (e.g. whether a Cloud Browser session must already be open), which keeps it from a 5.

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