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. 'Set' implies a mutation operation, but the description doesn't disclose behavioral traits like whether this requires specific permissions, if changes are reversible, what happens if the GameObject doesn't exist, or error handling for invalid tags. It mentions the tag 'must be defined in Unity Tag Manager' in the schema, but this critical constraint isn't reinforced in the description.

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 ('Set the tag'). There's zero wasted verbiage or redundancy. Every word earns its place by directly conveying the tool's purpose without unnecessary elaboration.

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 mutation tool with no annotations and no output schema, the description is incomplete. It lacks context on permissions, error conditions, side effects, or what success looks like. While concise, it doesn't provide enough information for an agent to confidently invoke the tool without risking errors (e.g., using undefined tags). The schema covers parameters but not behavioral context.

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 both parameters ('name', 'tag') clearly documented in the schema. The description adds no additional parameter semantics beyond what's in the schema—it doesn't explain naming conventions, tag validation, or examples. With high schema coverage, the baseline score of 3 is appropriate as the description doesn't compensate but doesn't detract either.

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 ('Set') and target resource ('tag of a GameObject'), making the purpose immediately understandable. It distinguishes from sibling tools like 'gameobject_find_by_tag' by focusing on modification rather than querying. However, it doesn't explicitly differentiate from other GameObject modification tools like 'gameobject_layer' or 'gameobject_active'.

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., GameObject must exist), constraints (e.g., tag must be predefined), or related operations (e.g., use 'gameobject_find_by_tag' to locate objects by tag). The agent must infer usage 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.