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

Annotations already set destructiveHint: true, so the description adds value by disclosing the RUN mode, the ability to generate assets, and the return field names. It does not contradict annotations and provides context beyond the safety flag.

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 concise (two sentences) and front-loaded with the core purpose. It includes usage and return info without wasted words, though it could benefit from clearer parameter coverage.

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 destructive, multi-purpose tool with four parameters and no output schema, the description is incomplete. It fails to explain project_id and image_urls, does not define what constitutes a valid instruction, and only lists return field names without detail.

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 description coverage is 0%, so the description must compensate. It explains video_id (target a specific video or omit for main video) and implicitly describes instruction, but completely omits project_id and image_urls, leaving them unexplained.

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 clearly states the verb ('Send ONE instruction') and resource ('editor agent'), with examples of what it may do (generate media, add to timeline, subtitles). It distinguishes itself as a general instruction tool among specific siblings like video_editor_add_clip, though it doesn't name an explicit alternative.

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 implies usage ('Call repeatedly to build the video') and explains video_id targeting, but it doesn't explicitly state when to use this tool versus the specific sibling tools (e.g., add_clip, set_transition). No exclusions or conditions are provided.

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