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

Annotations already declare readOnlyHint and openWorldHint, and the description goes well beyond them: cost ($0.03 USDC via x402 on Base), the conditional billing rule (charged only when two of three checks return data), the free-daily-call accounting, and an explicit scope disclaimer (facts only, no revenue/burn/fraud estimates). These are exactly the behavioral traits an agent needs before invoking a metered tool.

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?

The opening clause front-loads purpose and audience, and the signal list, output states, disclaimer and pricing each carry distinct information with no filler. It is on the longer side, but every sentence earns its place; only the audience enumeration is mildly expendable.

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 values need not be spelled out, yet the description still clarifies the found/not_found/unknown states. Combined with the billing conditions, free-call accounting and scope limits, an agent has everything needed to decide whether to call it and how to interpret the result.

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, so the schema already explains that the domain must omit scheme, path and port. The description adds only 'for one domain', which conveys cardinality but no new format or constraint detail beyond the schema. Baseline 3 is appropriate.

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 states a specific resource (a company domain) and enumerates exactly what it reports: ad/analytics tags, job board activity, and Google Ads Transparency entries. It is far more than a restatement of the name. However, it never distinguishes itself from the siblings that cover the same underlying signals (detect_website_tech_stack, get_company_open_jobs, get_google_ads_by_domain), so it loses the top mark for sibling differentiation.

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?

It names its target consumers (investment, due-diligence and vendor-risk agents), which implies the context of use, and the pricing/quota details help an agent weigh the call. But there is no explicit when-to-use versus when-not, and no routing guidance to the three sibling tools that surface the same signals individually.

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