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

With no annotations, the description carries the full behavioral burden and does add real domain context: codes never expire, the validity window is only a procedural calendar-year label, and results must be presented as discount codes rather than "standing codes". It still omits return shape and whether the operation is strictly read-only, but the semantic disclosure goes well beyond the name.

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?

Three tight sentences with no filler, and the core purpose is front-loaded before the semantic caveats and presentation rule. The final presentation instruction is slightly tangential but still functional.

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 five-parameter, filter-only list tool with no output schema or annotations, the description covers purpose, filter intent, and an important interpretation pitfall about validity windows. It does not describe pagination behavior or the returned record shape, which is a minor remaining gap.

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 100%, so all five parameters are already documented. The description reinforces the filter parameters (firm, active-only, minimum discount) but adds no syntax or format detail beyond the schema, and ignores limit/offset entirely. 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?

States a specific verb (List) and resource (prop firm discount codes) and even disambiguates the terminology a user might use ("coupon codes" / "promo codes"). However, it never distinguishes this tool from overlapping siblings like search_deals or latest_deals, so the agent gets no explicit routing signal.

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 names the available filters (firm name, active-only, minimum discount), which implies how to narrow results, but it never states when to choose this tool over search_deals/latest_deals or when it should not be used. Usage is implied rather than stated.

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