Compare two pages (or one page vs its latest Wayback snapshot); return what changed. (content; $0.008/call in USDC via x402, 25 free/day).
| Name | Required | Description | Default |
|---|---|---|---|
| url_a | Yes | Target URL or hostname. | |
| url_b | No |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations exist, so the description must disclose behavioral traits. It mentions pricing and payment method but omits details about output format, error handling, rate limits, or any side effects. The tool mutates no state, but an agent needs to know what 'changed' means and what to expect.
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: first clearly states purpose and result, second adds cost context. No filler, front-loaded, every word earns its place.
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 no output schema, the description does not explain the return format (e.g., diff text, JSON). It mentions 'return what changed' but lacks specifics. For a moderate-complexity tool with 2 params, this is a notable 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?
The schema describes url_a as 'Target URL or hostname' and url_b has no description. The description adds that if url_b is omitted, it compares to the latest Wayback snapshot, which clarifies the optional parameter's behavior. This adds significant meaning beyond the schema.
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 clearly states the tool compares two pages or a page vs its latest Wayback snapshot, returning what changed. This specific verb and resource distinguishes it from sibling tools focused on single-page actions.
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?
The description implies use when needing to identify changes between two URLs or against the Wayback, but does not explicitly mention when not to use or provide alternatives. It is clear enough for most contexts.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Add one secure layer between your agents and this server.
Most tools have clearly distinct purposes, but there are overlapping pairs: unfurl_url/get_oembed/find_favicon all provide URL metadata, and render_page/screenshot_page both render a page (render_page can also screenshot). Descriptions help disambiguate, so only minor confusion is likely.
Tool names mix verb_noun patterns (check_domain, extract_content) with noun_verb patterns (dns_lookup, ssl_lookup, whois_lookup). Additionally, guard_inspect and guard_tx deviate from the typical verb-first style. The naming is readable but not consistent.
With 19 tools, the server is at the heavier end of the scale. While it covers a broad web-intel toolkit, several tools feel out of place for a 'fetcher' (e.g., generate_qr, guard_tx, guard_inspect), making the set feel bloated and unfocused.
The core web-fetching and analysis surface is well covered: DNS, WHOIS, SSL, headers, content extraction, rendering, screenshots, feeds, embeds, redirects, and robots. Missing is a simple raw HTML fetcher, but extract_content and render_page likely cover most needs. The addition of security and utility tools doesn't fill obvious gaps.
