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

Annotations already declare readOnlyHint=true, idempotentHint=true, and openWorldHint=false, so the safety profile is covered. The description adds that the code is "static" and that output includes payload, SVG, and base64 PNG, which is useful context, but says nothing about output size costs, color/margin trade-offs, or whether the PNG scales with the size parameter.

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?

Two tight sentences with zero filler: the capability and its scope come first, the return artifacts second. Nothing is padded and nothing sentences-wise is wasted.

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?

An output schema exists, so the return-value sentence is supplemental rather than required. However, with ten parameters including two nested objects at 0% schema description coverage, the description leaves real gaps around ECC levels, sizing, and how wifi/vcard payloads condense to a single QR string.

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 carry the burden and it largely does not. It names the four content kinds that map to the `type` enum, but the other nine parameters (ecc, size, margin, dark, light, and the nested wifi/vcard fields) get no explanation, format, or interaction guidance.

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?

Specific verb ("Build") plus resource ("QR code") and an explicit scope of supported payload kinds (text, URL, Wi-Fi, vCard), which also flags that it is a static (non-tracking) generator. It never names a sibling such as read_barcode, the inverse operation, so per the rubric it stays at 4 rather than 5.

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?

There is no when-to-use or when-not-to-use guidance, no prerequisites, and no mention of alternatives among the many sibling tools. The content-type list is the only hint about applicability, and that information is already carried by the schema enum.

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