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

Annotations already declare read-only, non-destructive, open-world behavior, so the bar is lower. The description adds two useful behavioral facts beyond the schema: only active coupon entries are returned, and checkout acceptance depends on merchant conditions, warning the agent not to treat results as universally redeemable.

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?

A single compact sentence that front-loads the tool's function and appends the key caveat after a semicolon. No waste.

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 five optional search parameters and no output schema, the description is adequate for safety and purpose but thin on usage context. It does not explain how filters combine, what an empty-argument call returns, or when to prefer this over sibling discovery tools.

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%, with every parameter documented including query, store, country, page, and limit. The description adds no parameter meaning beyond the schema, 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?

States a specific verb and resource: 'Find active coupon entries in DiscountHub.' This clearly separates it from deal-oriented siblings like search_deals or get_best_deals, though it does not explicitly name an alternative or explain scope limits.

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?

There is no when-to-use guidance, no mention of alternatives such as search_deals or get_store_offers, and no prerequisites. The description merely states what the tool does plus a domain caveat.

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