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by io.github.pipeworx-io
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Image

image
Read-onlyIdempotent

Sample image metadata (returns URL).

Input Schema

TableJSON Schema
NameRequiredDescriptionDefault
formatYes

Output Schema

TableJSON Schema
NameRequiredDescriptionDefault
urlYesURL to sample image

Schema Changelog

Changes observed during successful MCP inspections.

  1. Changed2 schema fields changed
    • addedInput schema / examples
      Added value: +[
+  {
+    "format": "png"
+  },
+  {
+    "format": "jpeg"
+  }
+]
    • changedOutput schema / (root)
      Previous value: -nullNew value: +{
+  "properties": {
+    "url": {
+      "description": "URL to sample image",
+      "type": "string"
+    }
+  },
+  "required": [
+    "url"
+  ],
+  "type": "object"
+}
  2. First observed

TDQS

C2.4/5.0
Behavior3/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint=true and destructiveHint=false, so the agent knows it's safe. The description adds that it returns a URL, which is consistent. However, it does not disclose potential side effects (none expected) or rate limits, but annotations carry the burden.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness3/5

Is the description appropriately sized, front-loaded, and free of redundancy?

Single sentence, very concise and front-loaded. However, it sacrifices substance for brevity, omitting necessary detail. Every word earns its place, but it fails to be informative.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness2/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With one parameter and rich annotations, the description still needs to clarify the tool's function and parameter role. 'Sample' is vague. The lack of output schema visible (though context says present) reduces completeness. The description is insufficient for an agent to use correctly.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters1/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 0%, and the tool description does not mention the 'format' parameter. The schema only gives examples (png, jpeg) without explaining valid values or default. The agent has no semantic info about the parameter beyond its type.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose3/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description 'Sample image metadata (returns URL)' indicates the tool returns a URL, but 'sample' is ambiguous (test data vs. real placeholder). The name 'image' and input format parameter suggest image generation, but the purpose is not fully explicit. It distinguishes from siblings by name only.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines2/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

No guidance on when to use this tool versus alternatives. The description does not specify context, prerequisites, or that it provides placeholder images. The agent receives no help deciding when to invoke it.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

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