read_qrDecode QR code images to extract embedded text or URLs. Returns the decoded content. Use when you need to read what's stored in a QR code.
| Name | Required | Description | Default |
|---|---|---|---|
| url | Yes | Publicly accessible URL of the QR code image to decode. |
| Name | Required | Description | Default |
|---|---|---|---|
| decoded | Yes | The decoded text or URL extracted from the QR code |
Changes observed during successful MCP inspections.
Input schema / examplesPrevious value: -[
- {
- "url": "https://example.com/qrcode.png"
- }
-]New value: +[
+ {
+ "url": "https://api.qrserver.com/v1/create-qr-code/?size=200x200&data=https://pipeworx.io"
+ }
+]Output schema / (root)Previous value: -nullNew value: +{
+ "properties": {
+ "decoded": {
+ "description": "The decoded text or URL extracted from the QR code",
+ "type": "string"
+ }
+ },
+ "required": [
+ "decoded"
+ ],
+ "type": "object"
+}Input schema / examplesAdded value: +[
+ {
+ "url": "https://example.com/qrcode.png"
+ }
+]Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint, so the safety profile is fully covered without the description. The description adds only the return nature (decoded content); it says nothing about network fetch behavior, failure modes for undecodable images, or rate 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?
Three short sentences, purpose front-loaded, with no filler. The final sentence partially restates the first, which is a minor redundancy rather than padding.
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 single-parameter read tool with a full output schema and complete annotations, almost nothing is missing — return values are already covered by the output schema. The only shortfall is the absence of any guidance on sibling selection or failure behavior.
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 100% and the single url parameter is documented there as a "Publicly accessible URL of the QR code image to decode." The description adds no syntax, format, or constraint detail beyond that, so the baseline 3 applies.
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 (decode) and resource (QR code images) plus the output (embedded text or URLs), so the agent knows exactly what the tool produces. It never names its obvious sibling create_qr, so the inverse relationship is left to inference rather than made explicit.
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?
"Use when you need to read what's stored in a QR code" gives implied usage but restates the purpose rather than adding a decision rule. It does not mention create_qr as the alternative for the opposite operation, nor any precondition such as the image needing to be publicly reachable.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Add one secure layer between your agents and this server.