Unity API Communicator MCP Server

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It describes a read operation ('List'), implying it's non-destructive, but doesn't specify whether it requires specific permissions, how it handles errors (e.g., invalid material paths), or what the output format looks like (beyond mentioning 'values, types, and names'). For a tool with zero annotation coverage, this leaves significant behavioral gaps.

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 a single, well-structured sentence that efficiently conveys the core functionality without unnecessary words. It's front-loaded with the main action ('List all shader properties') and includes key details ('current values, types, and names') in a compact form, making it easy to parse.

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 tool with one parameter and no output schema, the description is minimally adequate. It covers the basic purpose and output structure ('values, types, and names'), but lacks details on error handling, permissions, or integration with sibling tools. Without annotations or an output schema, the agent must rely on the description alone, which is incomplete for robust usage.

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 100%, with the single parameter 'materialPath' fully documented in the schema as 'Asset path to the material'. The description adds no additional parameter semantics beyond what the schema provides, such as path format examples or validation rules. Given the high schema coverage, the baseline score of 3 is appropriate.

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 action ('List all shader properties') and the target resource ('a material'), making the purpose immediately understandable. However, it doesn't explicitly differentiate this tool from sibling material-related tools like material_color, material_float, material_shader, or material_texture, which appear to modify specific properties rather than list them all.

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 no guidance on when to use this tool versus alternatives. It doesn't mention prerequisites (e.g., whether the material must exist), nor does it compare it to sibling tools that manipulate material properties (material_color, material_float, etc.), leaving the agent to infer usage context from the tool name alone.

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