Timestamped public URL observations with SHA-256 fingerprints, paid in USDC on Base via x402.
Scored across 2 tools
The two tools have completely distinct purposes: one provides service information, the other performs the core observation action. No overlap or ambiguity exists.
Both tools use a verb_noun pattern ('freshproof_info' is slightly awkward but still noun-focused, 'observe_url' is clear). The prefix on one tool is a minor inconsistency.
With only two tools, the server is tightly scoped to its purpose: providing info and performing the single core action. This is well-calibrated for a focused service.
The domain is FreshProof observations, and the server provides the essential tools: information and observation. Minor gaps exist (e.g., no history or listing tools), but the core workflow is complete.
Describe FreshProof, its observation semantics, current MCP price and payment network. This tool is free.
| Name | Required | Description | Default |
|---|---|---|---|
No parameters | |||
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full burden. It discloses that the tool is free, which is a useful behavioral trait. However, it does not describe the return format, potential delays, or whether it performs any side effects (though as an info tool, side effects are unlikely). The description is adequate but not rich in behavioral detail.
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 with zero waste. The primary purpose is front-loaded, and the note about being free is appended clearly. 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?
For a zero-parameter informational tool, the description is complete: it tells the agent exactly what information will be provided. It doesn't specify the response format (e.g., plain text vs. JSON), but that's a minor omission given the tool's simplicity and the absence of an output schema.
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 tool has zero parameters, and the schema shows no properties. Per the rubric, a 0-param tool gets a baseline of 4. The description adds no parameter-specific meaning because there are no parameters to explain. The baseline score 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?
The description clearly states the tool's purpose: to describe FreshProof, its observation semantics, pricing, and payment network. It uses a specific verb ('describe') and names the exact subjects, making it unambiguous. It also distinguishes itself from the sibling tool 'observe_url' by focusing on informational content rather than observation 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 usage (call this when you need info about FreshProof), but it does not explicitly state when to use it vs. the sibling 'observe_url' or mention any exclusions. There is no direct guidance on when not to use it, though the contrast with the sibling is implicit.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Buy a timestamped FreshProof observation of a public HTTP/HTTPS URL. Returns final URL, observation timestamp, age, HTTP status, SHA-256 body hash, body size, ETag, Last-Modified, fetch duration, and whether the observation came from shared cache or a fresh public-network request. Set max_age=0 when a new public-network request is required. The response body itself is not returned.
| Name | Required | Description | Default |
|---|---|---|---|
| url | Yes | Public HTTP or HTTPS URL to observe | |
| max_age | No | Maximum acceptable observation age in seconds. Defaults to 300. Set to 0 to force a fresh public-network request. |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already signal read-only/non-destructive behavior; the description adds important behavior beyond that: shared-cache vs fresh-fetch semantics, the effect of max_age=0, the fact that the response body is never returned, and the full list of returned fields. This gives an agent an accurate model of what happens at call time.
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?
The core purpose is front-loaded in the first sentence, and the remaining sentences efficiently convey freshness control and the key exclusion ('response body itself is not returned'). 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?
Even without an output schema, the description enumerates all relevant return fields and explicitly states the body is not returned. For a two-parameter tool with safe annotations, this is complete enough for an agent to invoke it correctly without further inference.
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?
Both parameters are fully documented in the schema (100% coverage), so the description does not need to compensate. It reinforces the max_age=0 behavior already in the schema and adds the cache-vs-fresh nuance, but the incremental meaning over the schema is modest.
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 and resource: 'Buy a timestamped FreshProof observation of a public HTTP/HTTPS URL', immediately distinguishing it from the only sibling (freshproof_info). It also enumerates exactly what is returned, so there is no ambiguity about what the tool does.
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 gives clear operational guidance: use max_age=0 when a fresh public-network request is required, and otherwise an older cached observation is acceptable. It does not explicitly contrast with freshproof_info or state when not to use this tool, so it stops short of a 5.
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.
freshproof_infoobserve_url
Add one secure layer between your agents and this server.