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

Annotations already declare readOnlyHint and openWorldHint, and the description adds genuinely useful context beyond them: cost ($0.10 USDC per call on Base), the x402 payment mechanism, and the no-charge-on-failure guarantee. It does not describe latency or what data is returned, which keeps it from 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?

Two tightly written sentences with zero waste: capability first, then the billing constraint that materially affects invocation decisions. Nothing is buried or redundant.

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?

Payment terms and safety profile are well covered, but with no output schema the description should say what 'enrichment' actually returns (firmographics, tech stack, employee count, etc.). For a paid tool whose value depends on returned data, that gap matters.

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?

There is a single parameter with 100% schema description coverage ('Company domain, e.g. stripe.com'), so the schema already carries the semantic load. The description adds nothing about domain format, normalization, or subdomain handling, so the baseline of 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 action and resource: 'Company enrichment for one domain,' which tells an agent exactly what operation and scope to expect. The 'one domain' phrasing implicitly distinguishes it from the batch sibling, though it never names company_enrich_batch directly.

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 only implied by the scope phrase 'for one domain,' which suggests the batch tool handles multiple domains, but neither the alternative nor any exclusions or prerequisites are stated. An agent must infer when to pick this over company_enrich_batch.

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