[PAID $0.001 USDC/call, x402, eip155:8453] The Ed25519 public key that signs every fact, in hex, so a buyer can verify offline without calling us again.
This tool declares no required parameters. Add optional parameters from the input schema as needed.
{
"id": 1,
"jsonrpc": "2.0",
"method": "tools/call",
"params": {
"arguments": {},
"name": "fact_key"
}
}| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
Changes observed during successful MCP inspections.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the behavioral burden and does well: it discloses the price ($0.001 USDC/call), the x402 payment scheme, and the chain (eip155:8453). It implicitly signals a read-only, stable-key operation but does not state caching, idempotency, or response shape.
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?
One front-loaded sentence with the payment metadata bracketed up front and the purpose following immediately. Every clause earns its place; nothing is padded.
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 retrieval with no output schema, the description covers what is returned (hex Ed25519 public key), its role in verification, and the payment terms. Only the exact response envelope or field name is left unspecified, a minor 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 tool takes zero parameters, so there is nothing to disambiguate and the baseline is 4. The description correctly implies a no-argument call, and schema coverage is 100%.
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 states a specific resource: the Ed25519 public key, in hex, that signs every fact. An agent can immediately tell this is a key-retrieval endpoint distinct from fact_company or fact_verify, though it never names those siblings explicitly.
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?
It gives clear context for use: a buyer fetches this to verify facts offline without calling again. It stops short of stating exclusions or pointing to fact_verify/verify_attestation as the alternative path when online verification is wanted.
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.