pictor-mcp

Convert image format

image_convert

Convert images between JPEG, PNG, WebP, AVIF, TIFF, GIF, BMP, ICO, and more, while controlling quality, losslessness, and metadata.

Instructions

Convert an image between formats (JPEG, PNG, WebP, AVIF, TIFF, GIF, BMP, ICO, JPEG 2000, QOI, PPM), controlling quality, losslessness and metadata.

Input Schema

TableJSON Schema

Name	Required	Description	Default
`url`	No	http(s) URL to fetch. Disabled unless PICTOR_ALLOW_NET_FETCH=true.
`path`	No	Path to the image, relative to an allowed input root (or absolute inside one).
`effort`	No	Encoder effort: WebP method 0-6 or AVIF speed (inverted). Higher is slower and smaller.
`quality`	No	Lossy quality 1-100 (higher is better quality and larger).
`keep_icc`	No	Keep the ICC colour profile even when other metadata is stripped.
`lossless`	No	Use the codec's lossless mode where supported.
`background`	No	RGB colour used to flatten transparency when the target has no alpha channel.
`base64_data`	No	Inline image bytes as base64, optionally a data: URI.
`output_name`	No	Override the output filename (a safe name is derived if omitted).
`progressive`	No	Write a progressive JPEG.
`return_image`	No	Embed the resulting image inline so vision-capable clients can see it.
`return_base64`	No	Include the base64 payload in the JSON result for clients without file access.
`target_format`	No	Target codec, e.g. 'webp', 'png', 'avif'.	webp
`strip_metadata`	No	Remove EXIF/GPS/ICC metadata. Defaults to the server setting (on).

Output Schema

TableJSON Schema

Name	Required	Description
`ok`	No
`input`	No	Summary of the source image, when one was read.
`notes`	No
`steps`	No
`metrics`	No	Operation-specific measurements (e.g. comparison scores).
`outputs`	No
`operation`	Yes	Tool that produced this result.
`sizeChange`	No
`inlineImageIncluded`	No	True when an image block accompanies this result for vision-capable clients.

Schema Changelog

Changes observed during successful MCP inspections.

First observedv1.0.0Sep 15, 2026

TDQS

B3.3/5.0

Behavior2/5

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It states the core conversion action and mentions quality/losslessness/metadata controls, but it does not reveal operational traits such as whether the source is mutated, whether output files are written, how the result is delivered, or any restrictions like the PICTOR_ALLOW_NET_FETCH setting. This is a significant gap for a tool with zero annotation coverage.

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?

The description is a single, well-structured sentence that leads with the primary action and resource, lists supported formats, and summarizes the key controllable aspects. Every word earns its place; there is no filler or redundancy.

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?

Given the rich input schema and the presence of an output schema, the description need not repeat parameter details or return values. However, for a tool with 14 parameters and several close siblings, the description is slim on operational context and selection criteria, leaving the agent to infer too much about when and how to invoke it confidently.

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?

The input schema has 100% description coverage, so the baseline of 3 applies. The description adds minimal semantic value beyond the schema by loosely referencing quality, losslessness, and metadata, which maps to a few parameters but does not clarify the rest. Since the schema already documents all 14 parameters thoroughly, no compensation is needed.

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?

The description opens with a specific verb and resource: 'Convert an image between formats', then enumerates the supported codecs (JPEG, PNG, WebP, AVIF, etc.). This clearly distinguishes image_convert from its siblings like image_resize, image_crop, and image_rotate, and from image_compress or image_optimize_web, which target size reduction rather than format conversion.

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

Usage Guidelines2/5

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

The description gives no guidance on when to choose this tool over alternatives such as image_compress or image_optimize_web, nor any exclusions or prerequisites. The only usage signal is implied by the name and title, which is not enough for an agent to distinguish conversion from compression or optimization tasks.

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

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