Retrieve base64-encoded PNG data for a specific layer and frame from a LibreSprite file. Provides image data in a format suitable for direct use or further processing.
Return base64-encoded PNG data for one layer/frame's image.
| Name | Required | Description | Default |
|---|---|---|---|
| path | Yes | ||
| frame | No | ||
| layer | No |
| Name | Required | Description | Default |
|---|---|---|---|
| result | Yes |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description must carry the full behavioral burden. It discloses the return type (base64-encoded PNG), implying a read operation, but it does not mention error behavior, performance considerations, or any side effects. The lack of explicit read-only confirmation and absence of failure scenarios make this adequate but not thorough.
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?
A single, concise sentence conveys the core action without extraneous wording. Every word is meaningful, and the structure is front-loaded with the verb and outcome. There is no redundancy or filler.
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?
Despite having an output schema (not shown), the description fails to explain the three parameters adequately. With no annotations and zero schema descriptions, an agent lacks essential details about path semantics, frame/layer indexing, and potential edge cases. The tool is simple, but the description is incomplete for reliable usage.
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 coverage is 0%, so the description must compensate for the three parameters. It hints that 'layer' and 'frame' select which image, and 'path' presumably identifies the resource, but it does not define what 'path' refers to (file path, identifier, etc.) or clarify indexing (0-based vs 1-based). This is insufficient for reliable invocation.
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 ('Return') and a specific resource ('base64-encoded PNG data for one layer/frame's image'). It clearly distinguishes the tool from siblings like get_pixel (single pixel) or export_png (full export) by focusing on layer/frame-specific image data. However, it does not explicitly contrast with siblings, so it falls short of a perfect score.
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?
No guidance is provided on when to use this tool versus alternatives such as export_png or get_pixel. The description only states what it does, leaving the agent to infer the appropriate context from the name and sibling list.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.