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

Annotations already declare readOnlyHint/idempotent/non-destructive, so safety is covered; the description adds real value by disclosing the return payload shape (brand + active deal count + verified coupon count) and the 155+ brand coverage scope. It omits pagination behavior, which matters because the default limit of 100 is below the stated 155+ brand coverage.

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 first sentence is front-loaded and efficient, but the description then dumps 20 example brand names and an 8-item category enumeration that adds bulk without changing how the agent calls the tool. Roughly half the text is padding.

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 carries the burden of describing returns and does partially (deal and coupon counts, coverage volume). However it never explains that results are paginated/capped by limit, which is the key omission given 155+ brands vs. a 100 default.

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% and the schema already documents market, with_offers_only, and value ranges. The description only reinforces the category filter ('optionally filtered by category') and adds nothing about limit, market, or with_offers_only semantics, so it is baseline-adequate rather than additive.

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') and even names what the payload contains (active deal and verified coupon counts). It does not explicitly contrast itself with the closest sibling, list_categories, though 'Use list_brands for the full list' hints at the split.

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 a concrete trigger question ('Which brands do you cover?') so the agent knows the intent this tool serves. It never states when-not to use it or which sibling to prefer for filtered/brand-specific lookups, so it stops short of full routing guidance.

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