Scan up to 2,048 characters for common credential patterns and return only masked matches. Free, no wallet or account required. For larger inputs, use the $0.005 full scanner through the wallet-capable client: npx -y github:fablerlabs/x402-tools.
| Name | Required | Description | Default |
|---|---|---|---|
| text | Yes | Text to inspect. Maximum 2,048 characters. |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations exist, so description carries full burden. It states 'return only masked matches' and 'Free, no wallet or account required,' which are useful behavioral traits. However, it does not specify what happens if no credentials are found or what patterns are scanned, missing some transparency. Still, for a preview tool, it's largely sufficient.
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?
Three sentences: purpose, constraint/pricing, and alternative. No filler, front-loaded with key info. Every sentence adds value.
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 simple tool with one parameter, no output schema, and no annotations, the description covers purpose, input limit, cost, and how to handle larger inputs. Complete for intended use.
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% with one parameter 'text' described as 'Text to inspect. Maximum 2,048 characters.' The description repeats the length constraint but adds 'Free, no wallet...' which is not about parameter semantics. No new parameter-level meaning beyond 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?
Description clearly states 'Scan up to 2,048 characters for common credential patterns and return only masked matches.' This specifies the action (scan), resource (text), and outcome (masked matches). The sibling tool 'fabler_list_products' is unrelated, so no 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?
The description explicitly says 'Free, no wallet or account required,' indicating when to use this tool, and provides an alternative: 'For larger inputs, use the $0.005 full scanner through the wallet-capable client: npx -y github:fablerlabs/x402-tools.' This gives clear when-to-use and when-not-to-use guidance.
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.
The two tools have entirely distinct purposes: one lists product catalog and prices, the other scans text for credential patterns. There is no overlap or potential for confusion.
Both tools follow the consistent verb_noun pattern with the 'fabler_' prefix: 'list_products' and 'scan_secrets_preview', making them predictable and easy to understand.
With only 2 tools, the server feels very thin for its intended domain, which includes multiple paid services (full scanning, audit, OG cards) not yet available via MCP. The descriptions reference many missing capabilities.
The tool set covers only free, limited previews. Essential paid functionalities like full secret scanning and agent audit are completely absent from the MCP surface, creating severe gaps that agents cannot work around.
