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

Annotations are all false, so the description carries the burden of behavioral disclosure. It adds a useful policy: short EAN/UPC values get their check digit computed, and invalid ones are refused rather than corrected. However, it does not mention file-creation side effects, overwrite behavior, authentication needs, or that PNG output requires a Pro plan.

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 sentences, no filler, with the core action and output formats front-loaded. The check-digit behavior and QR alternative are stated economically, and every sentence earns its place.

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 the rich input schema that documents all eight parameters, the description provides the essential selection and behavioral context. The only notable gap is not distinguishing barcode_create from barcode_batch, but the tool can still be invoked correctly with the information provided.

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?

All parameters are already documented in the schema, so the baseline is 3. The description adds meaningful value by explaining that EAN/UPC check digits are computed and that a wrong one is refused, which clarifies the expected behavior of the value parameter beyond the schema.

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 states it draws a linear barcode, lists the supported symbologies, and names SVG/PNG as outputs. It explicitly differentiates from qr_create, though it does not address the barcode_batch sibling, leaving a small ambiguity between single and batch barcode generation.

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 description gives explicit context: this tool is for linear barcodes, and qr_create is the alternative for QR codes. It does not mention when to prefer barcode_batch or provide broader exclusion criteria, but the core usage signal is clear.

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