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 the full burden of behavioral disclosure. The description only states 'Select all' with a POST endpoint, implying a mutation action but without details on what gets selected, permissions required, side effects, or response format. For a tool with no annotations and a POST method (suggesting potential state change), this is inadequate, as it omits critical behavioral traits like whether it modifies scene state or requires specific user 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 concise and front-loaded with the core action ('Select all'), followed by technical details. It wastes no words, though it could be more informative. The structure is efficient, but the brevity contributes to under-specification rather than optimal clarity.

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 complexity (a POST tool with no annotations, no output schema, and nested input parameters), the description is incomplete. It lacks details on what 'all' refers to (e.g., objects, assets, scenes), behavioral context, and expected outcomes. Without annotations or output schema, the description should provide more guidance on usage and results, but it falls short, leaving significant gaps for the agent.

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 input schema has 1 parameter with 100% description coverage, providing a baseline score of 3. The description adds no parameter semantics beyond what the schema states (a 'params' object with JSON parameters), failing to clarify expected fields or usage. However, since schema coverage is high, the description does not need to compensate heavily, but it also adds no value.

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 'Select all (POST /api/selection/all) [Category: selection]' is tautological—it restates the tool name 'selection_all' as 'Select all' and adds only technical endpoint details. It lacks a specific verb+resource combination (e.g., 'select all objects in the current scene') and does not distinguish from sibling tools like 'selection_clear' or 'selection_set', leaving the agent guessing about what 'all' refers to.

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. The description does not mention context, prerequisites, or exclusions, and it fails to reference sibling selection tools (e.g., 'selection_clear', 'selection_set', 'selection_get'), leaving the agent with no basis for choosing this tool over others in the selection category.

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