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

Annotations are all-false and offer little baseline, so the description carries real weight. It adds a genuine safety guarantee (the link's public destination is not changed, consistent with destructiveHint=false) and reveals that the QR is 'recorded' persistently rather than merely rendered transiently, matching readOnlyHint=false. It stops short of explaining idempotency behavior (despite the idempotency_key parameter) or what happens to an existing QR for the same link.

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?

A single 17-word sentence that front-loads the verb and resource with zero filler. The scoping clause is the only addition and it earns its place by preventing misuse of the tool.

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?

Although the output schema covers the return side, this is an 11-parameter tool with zero schema descriptions and only a one-sentence tool description. An agent wanting non-default customization (eye_style, module_style, foreground_color, background, format) has no way to know valid values, and prerequisites beyond 'link exists' are unstated. The core happy path is clear but the full invocation surface is under-specified.

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 compensate, but it only hints at shortlink_id ('existing short link'). The remaining 10 parameters — size units, allowed format values, eye_style/module_style options, color formats, use_project_theme semantics, and idempotency_key purpose — are entirely undocumented in both schema and description.

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 specifies a concrete verb+resource pair ('Generate and record a QR asset') and scopes it precisely to an existing short link. The clause 'without changing its public destination' differentiates it from sibling operations like shortlink_create and shortlink_rotate, so an agent can tell what this tool does and does not do.

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 phrase 'for an existing short link' implies the prerequisite that the link must already exist, which gives some selection context. However, there is no explicit when-to-use statement, no named alternative, and no exclusions, so the agent is left to infer the usage scenario.

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