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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds valuable behavioral context by stating the tool returns 'citable answer guides and normalized records' and instructs the agent to 'Fetch the best returned id before giving detailed terms,' 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?

The description is four sentences of clean, front-loaded prose. Each sentence earns its place: the first gives scope, the second describes output, the third gives a required follow-up action, and the fourth gives exclusions. No fluff or repetition.

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?

With one parameter, an output schema, and safety annotations, the description provides enough to call the tool correctly. It even adds the important post-return instruction to fetch the best id. The main gap is not addressing the closely named sibling search_freebies, leaving some ambiguity about when to choose one over the other.

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 input schema already documents the single 'query' parameter with 100% coverage, including the natural-language savings question and suggested content. The description adds little about parameters beyond restating the query's role, so the baseline of 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 states a clear verb and resource: it searches current U.S. free trials, rebates, bonuses, cash back, and actionable savings, and it mentions returning 'citable answer guides and normalized records.' It does not explicitly differentiate itself from the sibling tool search_freebies, whose name suggests a nearly identical purpose, so it falls short of a 5.

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 explicitly says when to use the tool ('Use this when the user wants to find, compare, or answer a question...') and provides clear exclusions ('Do not use it for purchases, account access, or guaranteed eligibility'). However, it does not name any alternative tool such as search_freebies or fetch, so the when-not-to-use guidance lacks explicit routing to a sibling.

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