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

Without annotations, the description takes full responsibility for disclosure. It states the tool has no API, is browser-side, returns no scan verdict, error correction should stay at H, and stricter detectors like zbar reject phone-grade output. It even cautions to treat output as untested until physically scanned. This is thorough and honest about limitations.

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?

Despite being long, the description is front-loaded with the core purpose, then uses short paragraphs for non-generation, usage pairing, and limitations. Every sentence adds essential information; no fluff or repetition.

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?

Given there is no output schema and no annotations, the description is remarkably complete. It explains what the tool returns, what it does not do, what to pair it with, and practical caveats about scan reliability. An agent would have enough context to invoke it correctly and interpret its role.

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?

The tool has zero input parameters, so the schema is trivial and the baseline is 4. The description adds context about the nature of the parameters it returns (ranges, defaults, algorithm order), which helps understand the output but does not need to explain input semantics since there are none.

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 clearly identifies the tool as an information-returning tool that provides 'the parameters, ranges, defaults and algorithm order' for qart.uk's dithered photo QR recipe. It distinguishes itself from siblings by explicitly stating it generates nothing and pointing to get_qr_matrix for the module grid.

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?

It gives clear context: the tool is for implementing the technique yourself ('so that YOU can implement it or instruct someone who will') and it should be paired with get_qr_matrix. However, it does not explicitly enumerate alternative tools or state when not to use this tool, relying on the pairing note and the 'generates nothing' caveat to guide selection.

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