set_pie_window_size

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

Goes well beyond annotations: it discloses that the write persists to ULevelEditorPlaySettings, that it applies only to the NEXT PIE session while a running one keeps its current window, and it interprets the returned pie_currently_active flag as a warning that the on-screen state is stale. That is meaningful behavioral context for a tool annotated destructive/idempotent.

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?

Front-loaded with the purpose, then rationale, caveat, and alternative in a logical order; every sentence carries information. It is somewhat long for a three-parameter setter, but nothing is wasted.

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?

No output schema exists, so the description correctly documents the return shape (width, height, center, applies_to, pie_currently_active) and explains the semantics of the warning field. Nothing an agent needs to call and interpret this tool is missing.

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% and already documents clamping (160..7680, 120..4320) and the center default, so the schema carries the parameter burden. The description adds no additional syntax or format detail beyond what the schema provides; baseline 3 is appropriate.

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?

Specific verb+resource (set the Play-In-Editor window size) with explicit scope: it writes ULevelEditorPlaySettings, the same setting the editor's Play dropdown edits. It distinguishes itself from start_play_in_editor (which takes no size param) and render_widget_preview, so an agent can route correctly without opening schemas.

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?

Gives explicit when-to-use (reproducing headless UI bugs at resolutions the window doesn't happen to have, since start_play_in_editor offers no size parameter) and when-not-to-use (a single Widget Blueprint should use render_widget_preview with width/height/scale directly). Alternative is named with the condition that selects it.

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