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

Annotations already establish that the tool is read-only and idempotent. The description adds meaningful behavioral context by stating that comparisons rely only on facts from PeanutButterJelly.io's guides, which sets expectations about evidence sourcing and scope. No contradiction with 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 a single front-loaded sentence that conveys the action, the acceptable offer count, and the data source. There is no filler or redundant restating of the title.

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 simple one-parameter, read-only tool, the description plus schema and annotations is sufficient for an agent to invoke it correctly. The only minor gap is the absence of explicit routing guidance toward sibling tools, but that is not essential for correct invocation.

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%: the single parameter 'ids' is fully described with type, min/max items, and an example. The description adds no additional parameter-level semantics, 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 names a specific operation (side-by-side comparison), a clear resource (2 to 4 offers), and a grounding constraint (facts from PeanutButterJelly.io's guides). This clearly differentiates it from siblings like get_deal or search_deals, which handle single deals or searching.

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 explicitly defines when to use the tool: when comparing 2 to 4 offers. The min/max range also implicitly excludes single-deal lookups and larger comparisons, though it does not explicitly name sibling alternatives like get_deal for single-deal cases.

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