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

Annotations already declare readOnlyHint and openWorldHint, so the safety profile is covered. The description adds genuinely new operational context beyond annotations: cost ($0.002 USDC per successful call), payment rails (x402 on Base, Solana, or Arc), and the fact that failed calls are not charged — important for an agent deciding whether to retry. It does not discuss result volume or pagination behavior.

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?

Front-loaded with the resource and returned fields, then scope boundary, then sibling routing, then pricing. No filler sentences. The payment sentence is long but carries decision-relevant 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 only two fully documented parameters, an output schema, and read-only annotations, the description covers what an agent needs: what it returns, what it is not, which sibling to use instead, and what it costs. Missing only minor operational details such as result ordering or whether the listing is paginated beyond the limit parameter.

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 both parameters (keyword with 3–60 char range, limit 1–10 with default) are already fully documented in the schema. The description only restates that the search is 'for a keyword' and adds no constraints, format hints, or matching semantics (e.g., whether it is AND/OR, exact phrase). 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 resource (US federal grant opportunities from Grants.gov search2 API), enumerates the returned fields (opportunity number, title, funding agency, open/close dates, status, CFDA numbers), and specifies the query input (a keyword). It also draws a clear boundary — 'Opportunity listings only, not award decisions' — which distinguishes it from award-focused tools.

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?

Explicitly routes to alternatives with conditions: gov_sam_gov_wage_determinations for prevailing wage determinations and gov_sbir_government_grants for SBIR/STTR awards. The exclusion 'not award decisions' further narrows scope. It stops short of enumerating all grant-adjacent siblings or stating when this tool should be avoided entirely.

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