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

The description adds meaningful behavioral context beyond the annotations: the definition of discount as historical-high comparison rather than store list price, and the sorting by deepest discount first. Annotations already cover read-only/idempotent safety, so the description enriches rather than repeats.

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 two sentences, front-loads the primary purpose, and provides a crucial definition without any fluff. Every sentence earns its place, and the structure is efficient.

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?

The description covers the core behavioral nuance (discount definition) and is backed by an output schema, but it fails to explain parameter usage (especially sim and category) and does not mention pagination or result limits beyond the schema. Given 4 params and low schema coverage, more context is needed for full completeness.

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 description coverage is only 25% (only ending_within_days has a description). The tool description does not explain sim, limit, or category at all, leaving them ambiguous. With low schema coverage, the description should compensate, but it does not, so parameters remain under-specified.

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 purpose: listing add-ons that are discounted right now, ordered by discount depth. It also clarifies the resource (add-ons) and the specific criterion (current price below historical high). This distinguishes it from generic search or listing tools, though it does not explicitly name siblings.

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 when to use it (when current deals are wanted) but does not provide explicit when-to-use vs. alternatives, nor any exclusions. The discount definition helps avoid misuse (e.g., permanent markdowns), but no alternative tools are mentioned.

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