Barcode generator

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

Annotations declare readOnlyHint=true and idempotentHint=true, yet the description says the tool will 'write one file per value into a folder' and lets the caller pick an 'output' path — a filesystem side effect that readOnlyHint denies. Beyond that mismatch the description is genuinely informative (check-digit handling, invalid values non-fatal, subset C packing, system monospace font for PNG text), but the write-vs-readOnly conflict is a real inconsistency.

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 dense paragraph that is front-loaded with the output medium and symbologies, then moves to encoding rules and the value/values modes. Every clause carries information, though the run-on structure with semicolons makes it slightly harder to scan than it could be.

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 13-parameter tool with no output schema and no annotations covering return shape, the description covers output destination (file path vs folder), the default temp output folder, and the optional base64 return. It does not explain the result payload (does it return written paths?), file naming for the "values" mode, or overwrite behavior — gaps an agent would care about for a batch-writing tool.

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 the baseline is 3, but the description adds meaning the schema does not: EAN-13 accepts 12 digits and appends the check digit or 13 and verifies it, UPC-A works the same way, Code 128 takes printable ASCII with automatic subset C packing, Code 39 has a fixed charset plus optional mod-43, and value/values are alternative modes. Only the presentation parameters (scale, barWidth, height, colors) are left entirely to 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?

Opens with a specific verb+resource ('Make 1D barcodes as SVG or PNG') and then enumerates the four supported symbologies, immediately distinguishing it from qr_generate and the image_* siblings. An agent can tell exactly what this produces without opening the 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?

Explicitly states the two operating modes: supply "value" for a single barcode, or "values" (up to 1000) to write one file per value into a folder, plus the note that invalid values are reported rather than fatal. It stops short of naming a sibling alternative (e.g. qr_generate) or stating when-not to use it, so it does not reach a 5.

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