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

Annotations only cover safety/read semantics, yet the description adds substantial non-obvious behavior: this is a paid x402/USDC-on-Base resource with a time-decaying price ladder ($250 early, $25 last week, $0.01 post-publication). That price-by-lead-time behavior is essential and not derivable from annotations or schema. It stops short of stating whether each call re-charges (relevant given idempotentHint=false) or how payment is authorized.

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 sentences, front-loaded with what is delivered, then pricing, then the disambiguation. Dense but nearly every clause carries information; the parenthetical payment-rail detail is the only mildly incidental item.

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 should describe the returned artifact; it hints at 'our own index for BLS's six food-at-home groups' but never says the response shape, units, or whether the nowcast value and group indices both come back. Coverage of prerequisites and timing is good, but return-value completeness is partial for a paid data product.

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% and the month parameter already documents the YYYY-MM format and next-release default. The description adds the useful nuance that lead time to BLS's release drives price, which affects month choice, but supplies no month-format or validity detail beyond the schema. Baseline 3 applies.

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+resource ('nowcast of BLS's CPI food-at-home inflation, year on year') with scope (US high-low grocery chains, six food-at-home groups) and timing (before BLS publishes). The closing line 'For inflation questions, not company sales' explicitly separates it from the company-oriented siblings like find_companies and quote_sales.

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 clear negative boundary ('not company sales') and an implicit positive condition (inflation questions). It does not name a specific sibling alternative such as get_yoy_growth, so an agent must infer the routing itself, but the domain split is unambiguous.

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