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

Annotations already declare read-only, idempotent, non-destructive, and open-world behavior, so the bar is lower. The description adds geographic scope (U.S.), temporal scope (current), and return content (structured provider offers and destination links), which is useful beyond the annotations.

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 dense sentences with no filler. The use case is front-loaded, the return value is stated, and the exclusion/routing guidance is included without unnecessary detail.

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 annotations, zero required parameters, and an output schema, the description covers scope, return content, and sibling differentiation. Nothing essential for selecting and invoking the tool is missing.

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?

The description does not elaborate on individual parameters, but schema coverage is 60% with useful descriptions for query, category, and min_discount_percent, while sort and limit are self-documenting via enums/defaults/min-max. The schema bears most of the parameter burden, so the baseline 3 is appropriate.

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 opens with a specific use case: discovering or comparing current U.S. gift-card discounts across brands or categories. It names the resource and action clearly and distinguishes itself from get_gift_card_deals for exact single-brand lookups.

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?

It states exactly when to use the tool (discover/compare discounts across brands or category) and when not to (exact single brand when get_gift_card_deals can return the full provider set). This provides a clear selection rule and names the alternative.

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