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

Annotations only declare readOnly and openWorld, so the description carries the real burden and does add meaningful context: default ordering (newest first), the population boundary (announced completions only), and a full payment model — $0.002 USDC per successful call via x402 on Base, Solana or Arc, with failed calls not charged. That payment/auth disclosure is exactly the kind of trait annotations cannot express. It does not discuss rate limits, pagination or what a payment failure looks like, keeping it below a 5.

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?

Purpose and returned fields are front-loaded in the opening clause, with filtering, ordering and the price caveat following in priority order. Two sentences, no filler, and the cost notice is placed last where it does not obstruct tool selection.

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?

An output schema exists, so return-value documentation is not required, yet the description still names the returned fields. Combined with the ordering, scope exclusion and payment terms, an agent has everything needed to decide to call it and to anticipate the billing implication of doing so.

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 the baseline is 3. The description earns an extra point by specifying that the keyword matches against company, country or sector, which is field-level semantics the schema only hints at through examples ("GmbH, Texas, software, dental"). The limit parameter is left entirely to the schema, which is acceptable given its explicit 1–18 range and default.

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 and scope: "Recent M&A deals closed by Benchmark International, the mid-market sell-side adviser," then enumerates the returned fields (target, acquirer, deal summary, announcement link). This clearly separates it from the surrounding sibling tools, which are overwhelmingly company registries, review directories and job boards rather than deal-flow feeds.

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 usage context (browse newest-first, optionally narrow by keyword on company/country/sector) and a scope exclusion: only announced completed transactions, since confidential live mandates are not public. It stops short of naming an alternative tool or stating when a different sibling should be preferred, so it is not a full when/when-not pairing.

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