read_qr_codeDecode a QR code from an image URL or base64 data to retrieve the text it contains.
Decodes the QR code in an image and returns the text it holds.
| Name | Required | Description | Default |
|---|---|---|---|
| image | Yes | A link to the image, or the base64-encoded image bytes when format is `base64`. | |
| format | No | How `image` is given: `url` for a link, `base64` for the image bytes. | url |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations declare readOnlyHint=true and openWorldHint=true, covering safety and network access. The description adds that the result is the decoded text, which is useful since there is no output schema, but it does not mention failure cases, multiple codes, or rate limits. With annotations carrying the safety profile, this is a 3.
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?
One sentence, front-loaded with the action and result. Every word earns its place; no redundancy.
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 two-parameter read tool with full schema coverage and annotations for safety/open-world, the definition is nearly complete. The description covers the return value in the absence of an output schema, though it omits error behavior for invalid or QR-less images.
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 coverage is 100%: both image and format are fully described in the schema, including the base64 alternative and default. The description adds no parameter-level detail, so 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?
The description names a specific verb ('Decodes') and resource ('QR code in an image'), and states the output ('returns the text it holds'). This clearly separates it from generate_qr_code and other image tools without needing to name siblings.
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 description implies usage by stating the action, but gives no explicit when-to-use, when-not, or alternatives (e.g., generate_qr_code or inspect_image). An agent must infer that it applies only when an image contains a QR code.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.