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

With no annotations, the description carries the full burden and falls short: it never says whether this writes a file, returns an image URL/base64, requires auth, or whether generation is costly. 'high-resolution' is the only behavioral hint and it is unquantified.

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 front-loaded sentence with no filler. It is efficiently sized for such a simple tool, though it could have used the same space to disclose the output form.

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 generator the essentials are present, but with no output schema and no annotations the return contract (file path, URL, or inline image) is undefined, leaving the agent guessing what 'generate' produces.

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%, so 'text' and 'size' are already fully documented in the schema; the description's 'customized'/'high-resolution' wording only loosely gestures at the size parameter. Baseline 3 applies since the schema does the heavy lifting.

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?

States a specific verb (Generate) and resource (QR code image) plus the accepted input forms (URL or text). No sibling does anything similar, so sibling differentiation is moot rather than missing; the vague qualifier 'customized' is the only soft spot.

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?

No when-to-use, when-not-to-use, or prerequisite guidance. The 'from URL or text' phrase hints at acceptable input but is not framed as a usage condition, and there is no alternative tool offered for comparison.

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