BlenderMCP

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

With no annotations provided, the description carries the full burden. It discloses that the tool 'Returns a message indicating success or failure' (output behavior) and mentions the downloaded state prerequisite. However, it lacks disclosure of side effects (e.g., whether this overwrites existing materials, is reversible, or requires object selection).

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 efficiently structured with three distinct sections: the core action, parameter documentation, and return value. Every sentence earns its place by conveying essential information without redundancy, appropriate for a two-parameter tool.

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?

Given the absence of schema descriptions and output schema, the description adequately covers these gaps by documenting parameters and mentioning the return value. For a focused 2-parameter mutation tool, this is sufficiently complete, though explicit error conditions or sibling tool references would strengthen it further.

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% (properties lack descriptions), requiring the description to compensate. It successfully adds semantic meaning to both parameters: clarifying object_name references the target object and texture_id requires the download prerequisite. It provides adequate compensation but does not specify expected formats or validation rules.

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) and resource (Polyhaven texture) with the target (object). It implicitly scopes the tool to downloaded Polyhaven assets by mentioning 'previously downloaded,' but lacks explicit contrast with sibling download_polyhaven_asset to fully earn a 5.

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 workflow guidance by stating the texture 'must be downloaded first,' which establishes the prerequisite and implies the correct sequence with download_polyhaven_asset. However, it does not explicitly name the sibling tool or describe error states when the prerequisite is violated.

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