gthumb-mcp

Overview Schema Source Related Servers Discussions Admin

set_rating

Assign a 0–5 star rating to an image by writing embedded XMP and the gThumb comment sidecar, keeping ratings consistent in the gThumb UI and modifying the file.

Instructions

Set the gThumb star rating (0-5) of an image: embedded XMP (exiftool) and the comment sidecar the gThumb UI reads. This modifies the file.

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": {
      "path": "<path>",
      "rating": "<rating>"
    },
    "name": "set_rating"
  }
}

Input Schema

Name	Required	Description	Default
`path`	Yes
`rating`	Yes

Output Schema

Name	Required	Description	Default
`result`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.4.1Oct 27, 2026

TDQS

A4.2/5.0

Behavior4/5

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

No annotations are provided, so the description carries the full burden, and it does meaningful work: it discloses that the write goes to two places (embedded XMP via exiftool and the comment sidecar the gThumb UI reads) and explicitly warns 'This modifies the file.' It stops short of saying whether a prior rating is overwritten or what happens if the file lacks XMP.

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

Conciseness5/5

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

Two short sentences, zero waste, with the destructive warning front-loaded at the end of the first block rather than buried. No restatement of the tool name or filler.

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

Completeness4/5

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

An output schema exists, so return values need not be explained. For a two-parameter mutation tool with no annotations, the description covers the range constraint, the mutation warning, and the dual-write targets; only edge-case behavior (missing XMP, exiftool absence) is left unaddressed.

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

Parameters4/5

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

With 0% schema description coverage and no enum, the schema only says 'rating: integer'. The description supplies the critical constraint the schema omits: the rating is a star value bounded 0-5. The path parameter is left implicit but is self-evident from context.

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

Purpose5/5

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

States a specific verb and resource (set the gThumb star rating of an image) and immediately scopes it to the two storage locations it touches. That distinguishes it cleanly from the nearby set_comment and set_tags siblings, which write different metadata.

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?

The intended use is implied by the resource (image star rating in gThumb), so an agent can infer it belongs to a tagging/rating workflow. But there is no explicit when-to-use or when-not, and no mention of how it relates to set_tags or set_comment on the same file.

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