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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, so safety is covered. The description adds genuinely useful context beyond that: the cost model ('free within the daily allowance, then $0.003 USDC per call via x402') and the result ordering, which an agent would not know otherwise. It stops short of describing pagination or return shape, but those are covered by the output schema.

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 dense sentences with zero filler: scope and filters first, then the kind enumeration and default, then the pricing caveat. Every clause carries information an agent needs.

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 8 fully documented parameters, an output schema, and rich annotations, the description needs only to add what structured data cannot: the cost/allowance model and the default kind/sort. It does that. A brief note on pagination behavior would make it fully self-contained, but nothing essential is missing.

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%, so the baseline is 3. The description earns an extra point by surfacing the default for the kind parameter ('contracts (default)') and enumerating its values (contracts, idvs, grants or loans), which the schema does not state explicitly, plus the default sort order.

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 the resource (Federal awards) and the exact filter dimensions it accepts (keyword, recipient, awarding agency, date range), plus result ordering ('largest first'). An agent immediately understands this is a faceted award search rather than a single-record lookup, though it never names siblings like us-spending__award or us-spending__recipient to sharpen the distinction.

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?

Usage is implied by the filter list and the 'largest first' sort, so an agent can infer this is the browse/search entry point. However, there is no explicit when-to-use versus the sibling award/recipient lookup tools, and no guidance on whether filters are combinable or which are required (all are optional).

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