blender_list_materials

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

Annotations already declare readOnlyHint=true and idempotentHint=true, so the safety profile is covered. The description adds meaningful behavioral detail about what detailed=True returns, including node types and current Principled BSDF input values, which goes beyond the schema and annotations.

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 with no wasted words. It front-loads the core action and then adds the conditional detail behavior, making it easy for an agent to parse quickly.

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 simple read-only listing tool, the description covers the essential behavior: listing all materials and optionally returning detailed node and BSDF information. The absence of an output schema is partially mitigated by the description's mention of what detailed output includes, though the base return format is left implicit.

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 50%: response_format is already documented in the schema, while the 'detailed' parameter is undocumented there. The description compensates by explaining the effect of detailed=True, giving the parameter functional meaning beyond its bare boolean type.

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 states a specific verb and resource: 'List all materials.' It clearly distinguishes this from sibling tools like blender_list_images or blender_list_objects by naming the exact resource. The optional detailed mode is described, adding precision without ambiguity.

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 when to use this tool: when the agent needs to enumerate materials, and when to set detailed=True if node types and Principled BSDF values are needed. It does not explicitly exclude alternatives, but the resource name and sibling context make the intended use clear.

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