ue_engine_list

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

With no annotations, the description carries the full burden. It discloses the search locations (UE_MCP_ENGINE_DIRS, Epic Games Launcher list, Windows registry), giving good transparency about what the tool checks. No side effects or destructive actions are implied.

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 with three sentences, each providing essential information: purpose, search locations, and usage hint. No redundant or vague statements.

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?

While the description covers usage and search locations, it lacks details about the output format. Since there is no output schema, the agent does not know what the returned list contains (e.g., paths, versions). This gap reduces completeness.

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 tool has no parameters, so the schema provides full coverage. The description does not need to add param details. Baseline for 0 params is 4, and the description explains the tool's behavior 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 tool's purpose: listing Unreal Engine installations found on the machine. It specifies the search sources (environment variable, Epic Games Launcher, Windows registry) and distinguishes itself from sibling tools by focusing on engine discovery rather than project or editor operations.

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 explicitly advises to call this tool first when there is no project yet, providing clear usage context. It does not exclude other scenarios but implies a typical workflow order.

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