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

Annotations already declare readOnly, idempotent, and closed-world, so the safety profile is covered. The description adds genuinely new behavioral detail beyond them: output is a scalable vector file measured in millimetres and includes a link back to the generator. It stops short of covering failure modes (e.g., invalid value for a type) or whether the link expires.

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 dense sentences with the deliverable front-loaded and no filler. The main inefficiency is repeating the full 14-value type enum already present in the schema, which consumes space without adding information.

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 generation tool with no output schema, the description adequately covers what comes back (SVG/EPS in mm plus a link) and the GS1 sizing constraint. Minor gaps remain around error behavior for mismatched value/type combinations and how the returned link should be used.

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 schema already documents type, value, x_mm, format, gs1, and magnification. The description adds one useful fact not in the schema, the 80–200 magnification range for GS1 retail types, but otherwise restates the type enum that the schema already carries.

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 concrete verb and resource ('Draw a print-ready barcode') plus the return artifact ('SVG (or EPS) in millimetres, plus a link'). The enumerated type list makes clear this is a generator, cleanly separating it from sibling validators such as validate_gtins and calculate_check_digits.

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?

Usage is only implied: the description says what the tool produces but never states when to choose it over barcode_size, check_amazon_code, or identify_code. The one constraint given ('GS1 retail types use magnification 80 to 200') is a parameter rule rather than routing guidance.

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