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 states the tool creates a prefab instance but doesn't disclose behavioral traits like whether it requires specific permissions, if it modifies scene state permanently, what happens on invalid prefab paths, or if there are rate limits. The description is minimal and lacks operational context.

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, efficient sentence that front-loads the core action ('Instantiate a prefab in the current scene') and adds necessary clarification ('Creates a prefab instance linked to the original asset'). Every word earns its place with zero waste.

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 no annotations and no output schema, the description is incomplete for a mutation tool. It doesn't explain what the tool returns (e.g., success/failure, instance ID), error conditions, or side effects. For instantiating objects in a scene, more behavioral context is needed to guide an agent effectively.

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%, providing clear documentation for all 5 parameters. The description adds no additional parameter semantics beyond what the schema already covers (e.g., it doesn't explain parameter interactions or provide examples beyond the schema's descriptions). Baseline 3 is appropriate when schema does the heavy lifting.

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 ('Instantiate a prefab') and the target ('in the current scene'), specifying it creates a prefab instance linked to the original asset. This distinguishes it from sibling tools like prefab_create (creating new prefabs) and prefab_unpack (breaking prefab links).

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?

No guidance is provided on when to use this tool versus alternatives like prefab_create or gameobject_clone. The description mentions the current scene but doesn't specify prerequisites (e.g., scene must be open) or exclusions (e.g., cannot instantiate in closed scenes).

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