Check website uptime and changes since last check

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

Given readOnlyHint=false and idempotentHint=false, the description explains exactly why: it writes a private snapshot to the caller's Apify storage ('nothing on the target site changes'), runs on the caller's own Apify account with pay-per-event billing capped per run, and non-idempotency comes from baseline/diff semantics. It additionally discloses that blocked pages are not charged and that dates/UUIDs/copyright years are ignored by default to suppress false positives.

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?

Purpose is front-loaded in the first clause, then output shape, then the baseline/state workflow, then constraints and billing. The single-dense-paragraph format and the mid-sentence catalog of detection types partly duplicate schema descriptions, which costs a point but does not bury the critical information.

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?

Despite 18 parameters, an output schema, and stateful cross-call behavior, an agent has everything needed to call it correctly: required urls, baseline semantics, state reuse, cost multiplier, false-positive mitigations, and billing model. Return fields are covered by the output schema, and the description's summary of them is a bonus rather than a gap.

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 schema already carries the per-parameter text. The description still adds workflow-level meaning the schema cannot: stateStoreName must be reused across calls for comparisons, mode costs 3x in browser, and ignorePatterns/excludeSelectors exist specifically to suppress false changes. Some enumeration (prices, keywords, seoChecks, sitemap) largely restates schema properties, so it is not a full 5.

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?

Opens with a specific verb+resource: 'Checks web pages for uptime and for changes since the last check,' which cleanly separates it from siblings like full_website_audit (one-off audits) and fetch_clean_markdown (content retrieval). The enumerations that follow (uptime, diff, price/keyword/SEO change detection) confirm the scope without ambiguity.

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?

Explains the stateful workflow explicitly: the first call returns 'baseline' and later calls must reuse the same stateStoreName, and resetBaseline discards the snapshot. It also flags cost tradeoffs (browser mode 3x) and robots.txt blocking. It stops short of naming sibling tools or stating when not to use this versus a full audit, so not a 5.

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