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

Goes well beyond the readOnlyHint/openWorldHint annotations by disclosing the underlying access path (residential proxy), result density (~10 per page), and the billing model ($0.01 USDC per successful call via x402 on Base/Solana/Arc, failures free). It stops short of covering rate limits, latency, or failure modes, but the cost disclosure is exactly the kind of context an agent needs before spending.

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 the search scope and followed by the commercial terms. It is dense but every clause carries information; the field inventory is somewhat list-like and arguably redundant with the output schema.

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 an output schema present, the return-value burden is already handled, yet the description still summarizes fields. Combined with disclosed pricing, paging, and data source, an agent has enough to call it correctly; the missing piece is guidance on when to prefer a different directory source.

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%, so all four parameters are already documented with examples in the schema. The description only restates keyword plus city/state and adds 'about 10 per page', which implies the paging behavior but adds no new constraint (like the 1-10 page bound) 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?

States a specific verb and resource ('Manta US small-business directory search by keyword and city/state') and enumerates the returned fields, so the agent knows exactly what comes back. It does not explicitly name how it differs from nearby directory siblings like b2b_yellowpages or b2b_google_maps, leaving that distinction to be inferred from the source name.

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 search inputs are named, which implies when the tool applies, and 'about 10 per page' hints at paging. However, there is no explicit when-to-use/when-not guidance and no routing to alternative directory tools when a query is not a US local business.

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