ue_add_variable

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

The description discloses that the tool recompiles the blueprint and requires a specific engine version, but for a mutation tool with no annotations, it lacks details on side effects (e.g., saving, breaking references) and error conditions. This leaves the agent without full understanding of behavioral implications.

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 two well-structured paragraphs: one for purpose/requirement, one for parameter explanations. Every sentence adds value, and key info is front-loaded.

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?

The description covers inputs and requirements well but lacks output schema information and error handling. For a tool with 7 parameters and no annotations, it is adequate but not fully complete.

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 description adds significant value beyond the schema by explaining each parameter with examples and clarifying sub_type usage for structs/objects and class names. Given 0% schema description coverage, this fully compensates.

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 adds a member variable to a Blueprint and recompiles it, using specific action verbs and resource. It distinguishes from sibling tools like ue_create_blueprint or ue_add_component by specifying its unique function.

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 includes a requirement (UE 5.4+) and suggests checking ue_status for capabilities, providing context for when to use. However, it does not explicitly state when not to use or provide direct alternatives, though no similar sibling exists.

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