Unity API Communicator MCP Server

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

No annotations are provided, so the description carries full burden. It mentions the scene must be 'loaded', which is a prerequisite, but fails to disclose key behavioral traits: whether this is a destructive operation (e.g., unsaved changes in current scene), permission requirements, side effects, or what happens on success/failure. This leaves significant gaps for a mutation tool.

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, clear sentence with no wasted words, front-loading the core action. It efficiently conveys the essential purpose without redundancy or fluff, making it easy to parse quickly.

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 is a mutation (setting active scene) with no annotations and no output schema, the description is insufficient. It lacks details on behavior, error conditions, return values, or how it interacts with sibling tools. For a tool that changes system state, more context is needed to ensure safe and correct 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?

Schema description coverage is 100%, with the parameter 'path' well-documented in the schema. The description adds no additional semantic meaning beyond implying the path refers to a 'loaded scene', which is already covered. Baseline score of 3 is appropriate as the schema handles parameter documentation adequately.

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 ('set') and resource ('a loaded scene as the active scene'), making the purpose specific and understandable. However, it does not explicitly differentiate from sibling tools like 'scene_active' (which might retrieve the active scene) or 'scene_open' (which loads a scene), leaving room for ambiguity in sibling context.

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, stating only that the scene must be 'loaded' but not when to use this tool versus alternatives like 'scene_open' (which might load and set active) or 'scene_active' (which might query). No explicit when-not-to-use or prerequisite information is given, offering little help for selection among siblings.

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