Has this https URL changed? (sha256/etag). x402 $0.01 USDC, Base. As is, no warranty.
Scored across 1 tool
There is only one tool, so there is no possibility of confusing it with another tool. Its purpose—checking a URL for changes—is clearly stated.
With a single tool named 'url-change-check', there is no inconsistency in convention. The hyphenated descriptive name is clear and readable.
A single tool is narrowly scoped to the server's specific check operation, but one tool is thin for a server. It could reasonably support batch checks or history retrieval, making the count borderline.
The tool covers the full lifecycle for a stateless URL change check: fetch, hash, compare against prior sha256/etag, return change status, and include optional body preview. No obvious operation is missing for this purpose.
Fetch a public https URL, compute SHA-256 of the response body, and report whether it changed vs a prior sha256/etag ($0.01 USDC via x402). Sticky: store sha256 and call again later. Optional previous_sha256, previous_etag, include_body_if_changed. https only — http, file, data, localhost, and private IPs rejected. Caps: 1 MB body, ~10s timeout, max 5 redirects. Returns JSON { url, final_url, content_type, byte_length, sha256, etag?, last_modified?, changed, warnings, body_preview? }. As is, no warranty. Nothing stored.
| Name | Required | Description | Default |
|---|---|---|---|
| url | Yes | https URL to watch. http/file/data/localhost/private IPs rejected. | |
| previous_etag | No | Prior ETag; used when previous_sha256 is absent and response has ETag (quotes normalized). | |
| previous_sha256 | No | Hex SHA-256 of last seen body. If omitted (and no previous_etag match), this call is a baseline (changed=null). | |
| include_body_if_changed | No | If true and changed (or baseline), include truncated body text (~8KB) as body_preview. Default false. |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already cover the safety profile (readOnly, idempotent, non-destructive), and the description layers on substantial additional context: a $0.01 USDC x402 payment requirement, hard caps (1 MB body, ~10s timeout, 5 redirects), the https-only rejection list, and the explicit 'Nothing stored' / 'As is, no warranty' caveats. These are exactly the operational facts annotations cannot convey.
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?
Dense and front-loaded: the core action, then workflow guidance, then constraints, then return shape. Every clause carries information, though the caps/rejections/return-key enumeration makes it read as a list and slightly longer than strictly necessary.
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?
There is no output schema, and the description enumerates the returned JSON keys (url, final_url, content_type, byte_length, sha256, etag?, last_modified?, changed, warnings, body_preview?), so an agent can consume the result correctly. Combined with cost, limits, and storage semantics, nothing needed for correct invocation 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 schema already documents url, previous_sha256, previous_etag, and include_body_if_changed in detail (including quote normalization and the ~8KB preview cap). The description only restates the optional parameter names and the changed=null baseline rule, adding little beyond the structured fields. Baseline 3 applies.
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?
States a specific verb chain and resource: fetch a public https URL, compute SHA-256 of the body, report whether it changed vs a prior value. An agent knows exactly what this tool does and what it produces without opening the schema. No siblings exist, so differentiation is not required.
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?
Tells the agent the intended workflow explicitly ('Sticky: store sha256 and call again later') and describes baseline behavior when no prior hash is supplied. It does not spell out when-not-to-use cases beyond the https-only input restriction, but with no sibling tools there is no alternative to route against.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Recent tool additions, removals, and schema changes observed during successful MCP inspections.
url-change-checkhttps JSON URL to tidy markdown. x402 $0.005 USDC, Base. As is, no warranty.
https text to counts and sha256. x402 $0.005 USDC, Base. As is, no warranty.
HTML string or https URL to markdown. x402 $0.005 USDC, Base. As is, no warranty.
https CSV to headers and rows. x402 $0.005 USDC, Base. As is, no warranty.
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