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

Annotations already cover the safety profile (readOnly, idempotent, openWorld, non-destructive), so the bar is lower. The description adds genuinely new operational context not available in structured fields: the credit cost for developer API keys (15 credits) and the no-data-no-charge billing behavior. It still doesn't disclose response size or latency for what is obviously a large aggregate payload.

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?

Two compact sentences with the bundle contents front-loaded; little waste. 'Included in RivalSweeper plans' leans commercial rather than operational, but it carries real entitlement information, so it earns its place.

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 correctly compensates by enumerating what the bundle returns (promotions, price stats with samples, AI-readiness). For a composite tool this is close to sufficient, though it doesn't indicate how broad 'all current signals' is relative to the ~30 sibling signals, leaving payload expectations somewhat open.

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 100% with a single documented parameter, so the baseline is 3. The description adds only the framing that domain maps to a 'one brand-day' scope, which faintly implies a date dimension the schema does not actually expose, but contributes no format or validation detail beyond the schema.

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 names the resource concretely — a bundle of all current signals for one brand-day — and enumerates the contents (promotions, price stats + samples, AI-readiness). That distinguishes it from the many single-signal siblings like get_brand_price_statistics and get_active_promotions_and_coupons, though it never explicitly frames itself as the aggregate alternative to them.

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 phrase 'in one call' implies the intended use case (avoid many round-trips for a single brand), but there is no explicit when-to-use or when-not-to-use guidance relative to the individual signal tools. No prerequisites, freshness constraints, or exclusions are stated.

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