Valmera — AI Video Editor

Set background

set_background

Idempotent

Replaces the area behind the subject over a program window with a solid, gradient, blur, source image or frame, or strobe sequence. The subject can optionally be held at a specified time. Flash-safety rules apply; sound and zoom remain unchanged.

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "kind": "<kind>",
      "start": "<start>",
      "end": "<end>",
      "project_id": "<project_id>"
    },
    "name": "set_background"
  }
}

Input Schema

Name	Required	Description
`end`	Yes
`kind`	Yes
`start`	Yes
`style`	No	angle, radius, hold_f, stage
`colour`	No
`hold_t`	No
`source`	No	media key \| source second \| next \| previous \| FxSource
`colour2`	No
`sources`	No
`project_id`	Yes	Explicit project identifier for this request. The connection's navigation pointer does not select the target.
`hold_subject`	No

Schema Changelog

Changes observed during successful MCP inspections.

Changed2 schema fields changedNov 6, 2026

changedInput schema / properties / project_id / description

Previous value: -"Required immutable scope for this call. Copy the id from list_projects/open_project/project_state; the active-project pointer is never used to guess."New value: +"Explicit project identifier for this request. The connection's navigation pointer does not select the target."

addedInput schema / properties / source / type

Added value: +[
+  "string",
+  "number",
+  "object",
+  "null"
+]

AddedOct 15, 2026

TDQS

B3.4/5.0

Behavior3/5

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

Annotations already cover the safety profile (readOnlyHint=false, idempotentHint=true, destructiveHint=false), and the description adds genuinely useful boundaries: sound and zoom are unaffected, flash-safety rules apply, and the subject can be held at a time. It does not say what happens to any pre-existing background layer or how the mutation interacts with prior edges, which matters for a replace-style operation.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness4/5

Is the description appropriately sized, front-loaded, and free of redundancy?

Three tight sentences, front-loaded with the core action, then optional behavior, then constraints. No filler, though 'over a program window' is slightly opaque phrasing that could be sharper.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness3/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For an 11-parameter mutating tool with nested objects, one enum, no output schema, and low schema coverage, the description covers the main operation but omits several parameters an agent must still discover from the schema. It is adequate as an orientation but not fully self-sufficient.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

With 27% schema coverage across 11 parameters, the description does useful work by naming the kinds, the source image/frame option, the optional hold, and the program window implied by start/end. It leaves colour/colour2 pairing, the style object (angle, radius, hold_f, stage), the sources array, and the radial_blur enum value unexplained.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose4/5

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb and resource ('Replaces the area behind the subject') and enumerates the variants (solid, gradient, blur, source image or frame, strobe), so the operation is immediately identifiable. It does not distinguish itself from nearby siblings such as add_color_screen, add_strobe, or set_composite, leaving overlap ambiguity.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines3/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

Usage is only implied: an agent can infer this is the tool for swapping the backdrop behind a subject. There is no explicit when-to-use statement, no mention of alternatives for similar looks (e.g. add_color_screen vs a solid kind), and no stated prerequisites beyond the flash-safety note.

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

All Valmera — AI Video Editor tools Inspect

Try in Browser

One endpoint for every MCP toolRayrun runs every MCP server behind one URL and holds the credentials. Each call is decided per client, tool, and argument, then recorded.ray.runAd

Glama MCP Gateway

Add one secure layer between your agents and this server.