BlenderMCP

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

No annotations are provided, so the description carries the full burden. It mentions executing 'arbitrary Python code' and suggests a step-by-step approach, but fails to disclose critical behavioral traits: whether this is a read/write operation, potential side effects (e.g., modifying Blender scenes), authentication needs, error handling, or rate limits. The description is insufficient for a mutation-capable tool with zero annotation coverage.

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 concise with two sentences, front-loading the core purpose. The second sentence adds a usage tip but could be more integrated. There's no wasted text, though the structure could be slightly improved for clarity.

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 tool's complexity (executing arbitrary code in Blender), lack of annotations, no output schema, and low schema coverage, the description is incomplete. It doesn't explain return values, error conditions, or the scope of code execution (e.g., Blender API access), making it inadequate for safe and effective use.

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 description coverage is 0%, so the description must compensate. It lists the single parameter 'code' with a brief explanation ('The Python code to execute'), adding basic meaning beyond the schema's title 'Code'. However, it doesn't provide details on code format, constraints, or examples, leaving significant gaps in parameter understanding.

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: 'Execute arbitrary Python code in Blender.' It specifies the verb ('execute') and resource ('Python code in Blender'), making the action explicit. However, it doesn't distinguish this from potential sibling tools that might also execute code or interact with Blender in different ways, preventing a perfect score.

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 minimal guidance: 'Make sure to do it step-by-step by breaking it into smaller chunks.' This offers a vague suggestion on how to use the tool but lacks explicit when-to-use criteria, alternatives, or context compared to sibling tools like 'get_object_info' or 'set_texture'. No clear exclusions or prerequisites are mentioned.

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