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

Far exceeds the readOnly/openWorld/idempotent annotations: it discloses the source-routing rule (top 10 from Bing RSS, deeper results count>10 or page>1 from Brave), the fallback chain to Mwmbl, the disclosure fields in the response (source, sourceUrl, fallbackFrom), the 404-without-charge error semantics, and the paid x402 USDC pricing with the PaymentRequired handshake. These are non-obvious behaviors an agent cannot infer from the schema.

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?

Use case, return shape, source routing, operators, fallback, pairing, and payment are all front-loaded and each sentence carries information. The payment/error clauses are packed into a single dense run-on, which slightly hurts scanability, but there is no filler or repetition.

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 no output schema, the description carries the return-value burden and does so fully: fields returned, how the winning source is identified, and how empty results surface. Combined with the fallback and pricing behavior, nothing material needed to call this correctly is missing.

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%, so the baseline is 3, and the description adds real meaning on top: it ties count/page to which engine answers (Bing for the first 10, Brave for deeper pages) and documents the supported q operators (site:, "exact phrase", -exclude, filetype:). It leaves market/safe/count semantics to the schema, which already covers them adequately.

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 opens with a concrete verb+resource ('search the web') and enumerates the jobs it serves (research, fact finding, finding official pages/docs, competitor or link discovery, grounding with URLs). It states the return unit precisely (ranked organic results with position, title, url, domain, snippet). Scope within the ScrapeMole family ('Web search (SERP results)' vs news and suggest) is clear enough for an agent to route correctly.

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?

Explicit when-to-use framing ('Use when an agent needs to search the web: research, fact finding...'), plus an explicit follow-on partner ('Pair with ScrapeMole Reader /v1/read to turn a result URL into Markdown') and the fallback conditions under which the tool silently switches engines. An agent has enough to decide to call this and what to do with the output.

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