Adjust the field of view in the active Unreal Engine editor viewport to frame a scene wider or tighter. Use it to set perspective FOV in degrees for better viewing angles.
Set the perspective FOV (in degrees) of the active editor viewport
Returns: { applied: bool, requested: number, fov: number }
| Name | Required | Description | Default |
|---|---|---|---|
| fov | Yes | Field of view in degrees (positive; clamped to 5..170 by editor) |
Changes observed during successful MCP inspections.
v1.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=false, idempotentHint=true, destructiveHint=true, openWorldHint=false, so the safety profile is covered structurally. The description's genuine addition is the return shape { applied, requested, fov }, which matters because there is no output schema. It does not explain why this is flagged destructive or whether the change persists, so it adds modest but real value.
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?
Two short lines with zero filler: the action first, then the return shape. Front-loaded and easy to scan. Slightly terse but efficient.
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 single-parameter setter, the description covers what it does and what it returns, compensating for the absent output schema. Given annotations carry the safety profile, nothing critical is missing, though a note on persistence/undo would round it out.
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 the schema already documents the positive-degrees constraint and the 5..170 clamp. The description only restates 'in degrees.' Baseline 3 is appropriate when the schema carries the semantics.
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?
States a specific verb and resource: 'Set the perspective FOV (in degrees) of the active editor viewport.' This distinguishes it from the read-side sibling get_viewport_fov without needing the schema. It does not explicitly name siblings or scope itself against set_viewport_camera/set_viewport_exposure, so it stops short of a 5.
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 when-to-use guidance, no mention of alternatives (e.g., set_viewport_camera or set_camera_fov for a camera rather than the viewport), and no prerequisites. The agent must infer usage purely from the name.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.