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 explains the key behavioral difference between the two modes (replacement vs additive loading), which is valuable context. However, it doesn't mention other important behavioral aspects like whether this operation requires specific permissions, what happens to unsaved changes in the current scene, or what the response looks like (e.g., success confirmation, scene ID).

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 perfectly concise with just two sentences that each earn their place. The first sentence states the core purpose, and the second sentence explains the key parameter behavior. There's zero wasted language or redundancy, and the information is front-loaded with the most important details first.

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 creation tool with no annotations and no output schema, the description provides adequate but incomplete context. It explains the core functionality and parameter implications well, but doesn't address important aspects like what happens to the current scene's state, whether there are permission requirements, or what the tool returns upon success. Given the complexity of scene creation in a game engine context, more behavioral context would be helpful.

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 description adds meaningful context about parameter behavior that goes beyond the schema. While the schema has 100% coverage and documents both parameters with descriptions and defaults, the description explains the practical implications of the 'mode' parameter choices ('Single' replaces current scene, 'Additive' adds alongside existing scenes'), which helps the agent understand the semantic impact of parameter selection.

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 verb 'Create' and resource 'new empty scene', making the purpose specific and unambiguous. It distinguishes this tool from sibling scene tools like scene_open, scene_close, scene_save, and scene_setactive by focusing on creation rather than manipulation of existing scenes.

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 clear context on when to use different modes ('Single' vs 'Additive'), explaining that 'Single' replaces the current scene while 'Additive' adds alongside existing scenes. However, it doesn't explicitly state when to use this tool versus alternatives like scene_open or scene_save, nor does it mention any prerequisites or exclusions.

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