Create a thumbnail that fits within a square of a specified size while preserving the original aspect ratio.
Make a thumbnail that fits inside a square of the given size, keeping the aspect ratio.
| Name | Required | Description | Default |
|---|---|---|---|
| size | No | ||
| overwrite | No | ||
| input_path | Yes | ||
| output_path | Yes |
| Name | Required | Description | Default |
|---|---|---|---|
| width | Yes | ||
| format | Yes | ||
| height | Yes | ||
| output_path | Yes | ||
| output_bytes | Yes | ||
| max_dimension | Yes | ||
| original_size | Yes |
Changes observed during successful MCP inspections.
v0.3.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The annotations declare destructiveHint=true and readOnlyHint=false, so the safety profile is already known, but the description adds nothing about the important behavior of whether an existing output_path is overwritten, what happens when it already exists, or which formats are supported. It only restates the scaling rule, which is more purpose than behavior.
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?
It is a single front-loaded sentence with no filler and the key geometric constraint stated immediately. It is efficient, but it omits essential detail rather than being over-specified.
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?
An output schema exists, so return values needn't be described, but for a destructive write tool with four undocumented parameters, the description is not complete enough for confident invocation. Nothing covers overwrite semantics or failure modes.
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%, so the description must explain the four parameters, but it only hints at 'size' via 'square of the given size'. input_path, output_path, and especially overwrite, whose default is false, are undocumented anywhere, so this real gap cannot be compensated.
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 states a specific verb and result: it makes a thumbnail bounded by a square of the given size while preserving aspect ratio. That semantics distinguish it from the image_resize sibling, even though the sibling is not named explicitly.
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 offers no guidance about when to use this tool versus image_resize or image_crop, nor any prerequisites or exclusions. The usage context is only inferable from the word 'thumbnail'.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.