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

The description adds that it returns video_url, which is useful behavioral context beyond the annotations. However, annotations only include destructiveHint=false, so the description carries significant burden; it does not disclose potential asynchronous execution (sibling job_status suggests this may exist), rate limits, or prerequisites, leaving gaps.

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?

Two concise sentences with zero fluff. The main action is front-loaded, and the optional parameter behavior is stated efficiently. Every sentence earns its place.

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?

Given no output schema, the return value note is helpful, but the description omits the fit parameter meaning, does not mention whether the export is synchronous or async (despite job_status existing), and lacks preconditions. For a tool with 3 parameters and one enum, this is not fully complete.

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?

With schema description coverage at 0%, the description must compensate. It only explains video_id, not project_id or fit (the enum). This partial coverage adds some meaning but leaves the fit parameter and required project_id semantics undocumented.

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 uses a specific verb ('Stitch') and resource ('video's timeline into one MP4') while specifying features like transitions, audio mix, and burned-in captions. It also clarifies the optional video_id behavior, making it clearly distinct from sibling video_editor_export_captions.

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?

Provides clear guidance for the video_id parameter ('Pass video_id to export a specific video; omit to export the project's main video'), which is helpful context. However, it does not explicitly mention alternatives like video_editor_export_captions or state when not to use this tool, so it lacks explicit exclusions.

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