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

The key behavioral fact — 'opens nothing by itself' — is stated outright and is consistent with readOnlyHint=true, idempotentHint=true, and destructiveHint=false. It adds real context beyond annotations by explaining the tool is instruction-only and that execution happens through browser tools. The closing 'CapCut's official API: Partly.' is cryptic and adds confusion rather than clarity.

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 core workflow information is front-loaded and useful, but 'from ChatGPT, Claude or any AI agent' is promotional filler, and 'CapCut's official API: Partly.' is an unexplained fragment that costs a sentence without conveying a usable fact.

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, no-output-schema guidance tool, the description covers what the tool returns (screens, buttons, fields) and what it does not do (open anything), which is what an agent needs to route correctly. Missing only a note on what 'Partly' means for API coverage or any prerequisite about having a CapCut session open.

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 and 100% coverage, so there is nothing for the description to disambiguate. Baseline for a parameterless tool applies.

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 names a specific verb and resource (add auto captions in the user's CapCut account) and, crucially in the second sentence, redefines the tool as returning step-by-step instructions rather than acting. That clarification distinguishes it from the cotlet_browser_* siblings, though the opening sentence's phrasing ('Add auto captions...') briefly implies direct action before being corrected.

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 gives an explicit workflow: call this to get the steps, then perform them with cotlet_browser_* tools in the CapCut Cloud Browser. It names the alternative tool family and the condition under which to use it. No explicit when-not-to-use guidance, but the sequencing is clear.

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