ClaudeKit Blender MCP

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

The description adds valuable context beyond annotations: it specifies that the object must exist and material must be created first (prerequisites), and mentions it assigns to the 'active material slot' (specific behavior). Annotations cover idempotency (idempotentHint: true) and non-destructive nature (destructiveHint: false), but the description complements this with practical constraints. No contradiction with annotations exists.

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 well-structured with clear sections: purpose statement, prerequisites, parameters, return value, and usage guidelines. It's front-loaded with the core action. Minor redundancy exists (parameter info is in both schema and description), but overall it's efficient and every sentence adds value.

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 2 parameters, 100% schema coverage, and annotations covering key behavioral traits (idempotent, non-destructive), the description provides complete context. It includes prerequisites, specific slot behavior, return confirmation, and clear usage guidelines. No output schema is needed as the return is simple ('Success confirmation'), and the description adequately covers the tool's role in the workflow.

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 100%, with both parameters ('object_name', 'material_name') documented in the schema. The description repeats these parameter names and purposes in the 'Args' section but doesn't add significant semantic details beyond what the schema already provides (e.g., format constraints like pattern '^[a-zA-Z0-9_]+$' for object_name are only in schema). Baseline 3 is appropriate given high schema coverage.

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 specific action ('Apply existing material to Blender object') and resource ('object's active material slot'). It distinguishes this tool from siblings like 'blender_create_material' (which creates materials) and 'blender_set_material_property' (which modifies material properties rather than applying materials to objects). The verb 'apply' and target 'object's active material slot' are precise.

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 provides explicit guidance with 'Use when: Texturing objects after creating materials' and 'Don't use when: Material doesn't exist (create it first)'. It clearly indicates the prerequisite (material must exist) and references the sibling tool 'blender_create_material' as an alternative for when materials don't exist, making it easy for an agent to choose correctly.

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