オブジェクトの追加

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

With no annotations, the description carries the burden of behavioral disclosure. It adds important behavioral facts: overlapping frames in the same layer/scene are not handled correctly in AviUtl2 (and should be avoided), and frame_end is inclusive. This goes beyond the schema, though it doesn't cover error handling or permissions.

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 two sentences, front-loaded with purpose, and every sentence serves a purpose: it states what the tool does, gives a critical usage constraint, and clarifies frame_end semantics. No fluff.

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 tool with a complex nested schema, the description conveys the core purpose and the most critical constraint (overlapping frames). The schema itself contains detailed parameter descriptions, and there is no output schema requiring return-value explanation. The description could mention error behavior or atomicity, but it is adequate for most usage.

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 already provides descriptions for most parameters, but the description clarifies a key semantic: 'frame_end は終了フレーム(含む)' (frame_end is the end frame inclusive). The overlap warning also implies relationships between layer, scene, and frame ranges. However, it does not add extensive parameter details beyond this.

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 tool's purpose: 'プロジェクトにオブジェクトを追加する' (adds objects to a project), and explicitly enumerates supported types (video/image/audio/text/arbitrary effect composition). This distinguishes it from siblings like live_add_object by specifying the 'project' context.

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 gives a clear context for when to use (adding objects to a project) and includes a critical warning not to overlap frame ranges in the same layer/scene. However, it does not explicitly compare with sibling tools like live_add_object or update_object, so guidance on alternatives is only implicit.

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