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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive), and the description adds domain context: full coverage scale (160+ brands), the presence of deal/coupon counts in results, and the eight category groupings. It does not mention pagination behavior around the limit cap of 200, which is the main remaining gap.

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?

Purpose and usage are front-loaded well, but the middle section enumerates twenty example brand names and a full category roster, which is bloat for a tool-selection description. The closing 'Use list_brands for the full list' restates the name without adding routing value.

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 no output schema, the description usefully discloses what comes back (brands with deal and coupon counts) and the filterable axis. Pagination and the market restriction are the only meaningful omissions for a four-parameter list tool.

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 75%, so most parameters are already documented in the schema. The description restates the category filter and implies the offers-only behavior via 'number of active deals and verified coupons', but says nothing about limit or market. 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 ('List the brands MoneyDeals covers') plus what is attached to each result (active deals and verified coupons) and the optional category filter. It is clearly distinguishable from list_categories and search_deals, though it never names those siblings explicitly.

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?

Gives an explicit use case ('Which brands do you cover?') and notes the optional category narrowing. It does not state when to prefer search_deals or list_categories instead, so the routing against siblings is left to inference.

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