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

With no annotations provided, the description carries the full behavioral burden and does meaningful work: it discloses that the call is paid ("Costs $0.003 USDC on Base via x402"), which is critical for an agent deciding whether to invoke it. It also enumerates the result shape, since no output schema exists. It omits rate limits, caching/latency, and failure behavior for URLs never archived, 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 sentences, front-loaded with the resource and primary scope, followed by use cases and then cost. The long comma-delimited field list is dense but each element earns its place because there is no output schema to convey return fields. Slight deduction for list density over prose clarity.

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?

Given a single-parameter tool with no annotations and no output schema, the description supplies the two things an agent most needs: what comes back and what it costs. Missing are edge-case behavior (unarchived domains, redirects, internationalized URLs) and any hint about latency or error responses, which matter for a paid external call.

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 description coverage is 100%, with the single required 'url' parameter documented as "Domain or page URL (stripe.com)". The description adds no further meaning about the parameter — whether a bare domain is normalized to https://, whether a specific page path yields page-level rather than domain-level history, or how the pattern constraint behaves. Baseline 3 is appropriate when the schema already does the work.

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 verb and resource — a website's archive history from the Internet Archive's Wayback Machine — and then enumerates the exact payload (first/last capture, years and months archived, activity by year, longest gap, last HTTP status, snapshot links). This is clearly distinguishable from siblings like domain_lookup, website_audit, and website_tech_stack, which address WHOIS, audits, and tech detection rather than archive continuity.

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 states concrete usage contexts: domain age assessment, due diligence, and spotting parked or re-registered domains. That is enough for an agent to recognize the right situation, but it never names a sibling alternative or an exclusion (e.g., use domain_lookup instead when you need registration dates rather than archive activity), so the routing burden remains partly on the agent.

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