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

Annotations already cover read-only and open-world behavior, and the description adds genuinely new context: the $0.01 USDC x402 charge and that billing only occurs on success — important for an agent deciding whether to call. It omits not-found behavior (empty result vs. error) and what the exclusion flag means in practice.

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, zero filler: the capability and returned fields come first, and the pricing caveat is appended where it belongs. Every clause carries information.

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 compensates well by listing the returned attributes (status, expiration, CAGE, exclusion flag, NAICS, business types). Remaining gaps are minor: not-found semantics and whether both lookup keys may be supplied together.

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 both parameters are documented there, including the 12-character UEI format and that name is an alternative to uei. The description restates the same two keys without adding format, precedence, or mutual-exclusivity rules, so the 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 (look up), resource (US federal contractor), source (SAM.gov), lookup keys (UEI or legal business name), and enumerates the fields returned. An agent can distinguish it from siblings like screen_counterparty or check_motor_carrier_safety without opening a schema.

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 description makes clear this is the SAM.gov registration/exclusion lookup and that either a UEI or legal name can be supplied, which is real invocation guidance. It stops short of naming exclusions or pointing to a sibling (e.g. screen_counterparty) for related but different checks, so no explicit when-not guidance.

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