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

Annotations cover the safety profile (readOnlyHint=false, idempotentHint=false, destructiveHint=false), and the description adds substantial context beyond them: the 30-minute post-approval validity window, cross-shop reuse of the id, and the self-updating AltID card behavior. It also warns 'Never make your own QR code', a genuine operational constraint.

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 critical condition ('Only when... several shops') is front-loaded, and every sentence carries information. Slightly run-on parentheticals make it denser than ideal, but nothing is wasted.

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?

No output schema exists, and the description implicitly conveys the return (an age_check_id to reuse) plus the visible card behavior. Complete enough for a one-parameter tool, though the returned payload shape is only inferable.

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 baseline is 3, but the description adds real meaning: min_age should be the highest age limit across all the orders and is sourced from get_menu/quote_order. This goes beyond the schema's bare 'The age to confirm, e.g. 18'.

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+resource ('start one age check with AltID') and immediately distinguishes itself from the sibling place_order for the single-shop case. An agent can tell exactly what this tool creates and when it differs from alternatives.

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 scopes use to multi-shop orders containing age-limited products, names the exclusion (single-shop orders should call place_order, which shows the card itself), and instructs how to reuse the returned age_check_id. When/when-not/alternative are all present.

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