scan_barcode

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

No annotations exist, so the description carries full burden. It discloses sources (Open Food Facts, FDA), the matching against Clarity's database, and the recall verification via source_url. It does not explicitly state read-only nature, but the actions are clearly non-destructive. No contradictions.

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?

The description is a single sentence that front-loads key actions (look up, match, return, flag). It is informative but slightly long; could be split for readability. No wasted content.

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 no output schema, the description explains returned data (flagged ingredients and recall info with source_url). However, it omits details on the format of flagged ingredients, error handling (e.g., barcode not found), and potential limitations. Adequate but not fully comprehensive.

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% with basic descriptions. The tool description adds context: lens is used for flagging ingredients, barcode lookup sources. This enhances understanding beyond schema, meriting a score above the baseline of 3.

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 the tool's purpose: look up a barcode from Open Food Facts / Open Beauty Facts, match ingredients against Clarity's database, flag ingredients for a given lens, and flag FDA recalls. It clearly distinguishes from siblings like check_ingredient or check_recall by combining these actions.

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 implies usage when a barcode is available and ingredient/recall analysis is needed, but does not explicitly state when to use it over alternatives (e.g., check_ingredient for ingredient-by-name queries). No exclusion criteria or comparative guidance is provided.

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