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

Annotations already declare readOnly, idempotent and non-destructive, so the safety profile is covered. The description adds real value beyond that: the return payload (PNG image plus editor link), the no-persistence/no-account guarantee, and the permanence caveat that a static code cannot be changed after printing — a materially useful behavioral fact for a preview 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?

Three sentences, front-loaded with the action and output, followed by the editor/download path and the static-code caveat. Dense with no filler; the type enumeration is long but functional rather than redundant 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?

There is no output schema, and the description compensates by describing both return artifacts (PNG image and editor link). For a 20-parameter, single-required-field preview tool, the description plus a fully documented schema cover everything an agent needs to call it and interpret the result.

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 every one of the 20 parameters is documented in the schema, including conditional 'type ...' prefixes. The description only restates the type list already captured by the enum, adding no format, constraint or dependency guidance beyond the schema, 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?

"Draws a black and white preview of a static QR code" states a specific verb and resource, and the enumerated content types (web address, plain text, email, phone, SMS, WiFi, contact card) pin down exactly what the tool covers. The word "static" plus "Nothing is saved" cleanly separates it from the sibling create_dynamic_link_code, so an agent can route without opening a schema.

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?

Clear context for use: preview-only, no account, nothing persisted, with a pointer to the qrforprint editor for styling and download. It implies the alternative (persisted/dynamic codes handled by the sibling tools) but never names or explicitly excludes them, so the routing is inferential rather than stated.

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