Loads a local image or graphic file from an absolute or relative path, converts it to Base64, and returns a data URL for canvas use.
Reads any local image or graphic file from the user computer (absolute path e.g. "C:/Users/name/Desktop/logo.png" or relative path), encodes it to Base64, and returns the data URL for use in canvas.
| Name | Required | Description | Default |
|---|---|---|---|
| filePath | Yes | Absolute or relative local file path on the computer |
Changes observed during successful MCP inspections.
v1.0.7Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden and does disclose the meaningful behavior: it reads from local disk, encodes to Base64, and returns a data URL rather than a file handle. It does not mention failure modes (missing file, permission denied) or size/format limits, which is the remaining gap.
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 well-formed sentence that front-loads the verb and resource, then appends the return value. No filler, no restatement of the title, and the example is inline rather than a separate paragraph.
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 one-parameter read tool with no output schema, the description usefully specifies the return artifact (data URL), removing the biggest ambiguity. It is only slightly short of complete because 'any local image or graphic file' leaves supported formats and file-size constraints unspecified.
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?
Only one parameter and schema coverage is 100%, so the baseline is 3; the description earns an extra point by supplying a concrete example path format ('C:/Users/name/Desktop/logo.png') and explicitly confirming relative paths are accepted, which is more actionable than the schema's generic wording.
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?
States a specific verb (reads), a specific resource (any local image or graphic file on the user's computer), and the full transformation pipeline (Base64 encode -> data URL). This is clearly distinguishable from siblings like assets_list_local (which enumerates) and image_add (which places an image already in the project).
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 trailing clause 'for use in canvas' hints at the intent, but the description never states when to pick this tool over assets_list_local, image_add, or element_add_stock. No preconditions or exclusions are given, so the agent must infer the selection rule.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.