Convert and resize images between WebP, AVIF, JPEG, and PNG formats while controlling dimensions and quality settings.
Convert/resize an image. Formats: webp, avif, jpeg, png (lossless).
For webp/jpeg, quality is 0-100; for avif, quality is a CRF-like value.
| Name | Required | Description | Default |
|---|---|---|---|
| fmt | Yes | ||
| input | Yes | ||
| width | No | ||
| height | No | ||
| output | Yes | ||
| quality | No | ||
| overwrite | No |
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full behavioral burden. It discloses format support and quality interpretation, but it does not explain whether the operation overwrites files by default, how existing outputs are handled, whether resizing preserves aspect ratio, or what permissions/access constraints apply.
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?
The description is short, front-loaded, and contains no wasted text. The core operation is stated first, followed by the two pieces of format/quality context that are most likely to affect invocation.
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 7-parameter image-conversion tool with no annotations, the description is incomplete. The output schema covers return values, but the description still omits key invocation details such as overwrite semantics, resizing behavior, and input/output path handling.
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 0% across 7 parameters. The description adds useful meaning for fmt and quality, including valid formats and quality ranges, but leaves input, output, width, height, and overwrite undocumented in both schema and description.
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?
The description clearly states a specific verb and resource: convert or resize an image. It also lists supported output formats, so the agent can distinguish this from video/audio sibling tools without opening the schema. It does not explicitly differentiate itself from the closest image-related sibling, thumbnail.
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?
The description explains supported formats and quality semantics but gives no guidance on when to use this tool versus alternatives such as thumbnail or transcode_video. There are also no prerequisites or exclusions for input/output files, overwrite behavior, or required dimensions.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.