Convert pixel coordinates on a calibrated scanned page into real-world millimeter measurements, or reverse millimeters back to pixels, for accurate CAD scaling.
Convert pixel positions on a calibrated page to real mm (and back with mm_points).
| Name | Required | Description | Default |
|---|---|---|---|
| page | No | ||
| scan_id | Yes | ||
| mm_points | No | ||
| px_points | No |
Changes observed during successful MCP inspections.
v0.2.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full behavioral burden. It does not state whether an uncalibrated page errors, whether supplying both px_points and mm_points is invalid, precedence rules, or what the response shape is — all material for a coordinate-transform tool.
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 with the core verb and resource first, and the reverse-mode hint parenthesized. No filler, though the brevity comes partly at the cost of necessary detail elsewhere.
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?
With no annotations, no output schema, and four parameters at 0% schema coverage, the description leaves the agent without error behavior, return format, or the meaning of half the parameters. It is too thin for a geometry-transform tool that depends on prior calibration state.
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 compensate and only partially does: it explains the roles of px_points and mm_points (input/output direction). It says nothing about the required scan_id or the page parameter and its default of 1.
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+resource ('Convert pixel positions ... to real mm') and even notes the reverse direction via mm_points, so the agent knows exactly what the tool computes. It does not differentiate from siblings, but no sibling competes for this conversion job.
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?
'on a calibrated page' implies the prerequisite that calibration must precede use, and naming mm_points implies the reverse-direction mode. However, there is no explicit when-to-use/when-not guidance, no mention of what happens on an uncalibrated page, and no named alternative for related scan operations.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.