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

Beyond the readOnly/openWorld annotations, it discloses a real cost model ($0.002 in USDC per successful call, x402 on Base/Solana/Arc, failures not charged), a hard result cap of 25, and the subtle behavior that the state filter applies to those 25 rather than the full corpus. These are exactly the facts an agent must know before spending money or misreading results.

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 core purpose and the output fields, with the billing caveat last. The long field enumeration is somewhat redundant given an output schema exists, but every sentence still carries usable information and nothing is padded with filler.

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 description does not need to re-explain return values, yet it summarizes them anyway; combined with annotations, full schema coverage, pricing, payment path, and the filter-ordering caveat, an agent has everything needed to invoke this correctly and anticipate the charge.

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, but the description adds semantics the schema only hints at: the limit is implicitly capped at the top 25, and crucially that 'state' filters the already-limited set, not the whole supplier universe. That post-filter caveat materially changes how an agent should sequence limit and state.

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?

The description names a specific source (Thomasnet), a specific resource (US/Canadian industrial suppliers), and the exact query input (a product or service term such as valves or CNC machining). The enumeration of returned fields makes it unmistakable what this tool produces versus a generic people/company lookup sibling.

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 scope: query a product or service term to get suppliers, with examples ('valves, CNC machining') illustrating the right input shape. However, it never states when to pick this over the many sibling directories (b2b_indiamart, b2b_yellowpages, b2b_manta, b2b_google_maps) or any exclusion. Guidance exists but only by inference.

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