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

Annotations already declare read-only and idempotent behavior. The description adds meaningful behavioral context: it returns a prompt and upload/material steps, delegates image generation to the harness, and does not consume Blender compute. This goes beyond the annotations without contradicting them.

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 three tight sentences with no filler. It front-loads the core purpose in the first sentence, then efficiently adds the return behavior and the key non-behavior (no image generation, no Blender compute).

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?

The description covers high-level purpose and safety-relevant behavior, but it is thin for a tool with 19 parameters, nested objects, and no output schema. The return value is only vaguely described as 'a prompt and upload/material steps,' with no detail on output structure or how to translate inputs into those steps.

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 19 parameters and only 32% schema description coverage, the description needed to compensate by explaining how to choose or fill key fields like purpose, workflow, layout, or requestedMapRoles. It does not mention any parameter semantics beyond listing use categories, so most of the parameter burden remains on an under-covered schema.

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 ('Plan') and resource ('source image'), enumerates concrete use cases, and explicitly differentiates itself from generation by stating the harness calls its own image tool. This clearly distinguishes it from sibling tools like asset_generate_3d or render_create.

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 and scope: planning source images for surfaces, decals, trim sheets, animation, etc. It also states what the tool does not do, implying when it isn't appropriate. However, it never explicitly names alternative tools or says 'use X instead,' so the routing guidance is implicit rather than explicit.

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