Fetch an image by its ID and return it as a base64-encoded string, enabling direct embedding, sharing, or processing in scripts and APIs.
Get an image as a base64-encoded string.
| Name | Required | Description | Default |
|---|---|---|---|
| image_id | Yes | ID of the image |
| Name | Required | Description | Default |
|---|---|---|---|
| data | Yes | Base64-encoded image data with data URI prefix | |
| message | Yes | Status message | |
| image_id | Yes | Image ID |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations are absent, so the description carries the full burden of behavioral disclosure. It only restates the action ('Get an image as a base64-encoded string') without mentioning read-only nature, side effects, permission requirements, or any constraints. The implied read operation is not explicitly stated, and there is no mention of error behavior or size limits.
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, front-loaded sentence that precisely conveys the action and output format. There is zero redundancy; every word earns its place. It is appropriately concise for a simple getter tool.
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 simple tool with one parameter and an output schema (present), the description covers the core purpose. However, it omits any mention of when to use this over get_image or any prerequisites (e.g., how to obtain an image_id). The absence of usage guidance and explicit behavioral notes makes it slightly incomplete, but the simplicity of the tool and the presence of an output schema mitigate the gap.
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?
The schema already documents image_id as 'ID of the image' with 100% coverage. The description adds no additional parameter context, such as format, source, or how to obtain a valid ID. Baseline 3 applies because the schema fully covers the parameter, and the description does not need to compensate for gaps.
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 ('Get'), a resource ('an image'), and a specific output format ('base64-encoded string'). This clearly distinguishes it from sibling tools like get_image (likely returning a file or object) and list_images (which lists). It leaves no ambiguity about what the tool does.
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 like get_image, load_image, or capture_screenshot. The description only states the action, leaving the agent to infer appropriate usage from the format difference. There are no explicit exclusions or conditions.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.