Verify claims against observed evidence with fail-closed logic, returning confirmed, refuted, or unverified results plus a SHA-256-bound tamper-evident report.
Fail-closed claim verification. Each claim has text, predicate, observed and expected. Returns confirmed/refuted/unverified and a SHA-256-bound report.
| Name | Required | Description | Default |
|---|---|---|---|
| claims | Yes | ||
| reported_hash | No |
Changes observed during successful MCP inspections.
v0.3.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden, and it does disclose two real behavioral traits: fail-closed semantics and the three possible verdicts. It says nothing about error behavior, what the SHA-256 binding is for, or why a caller would supply a hash, leaving meaningful gaps for a verification tool.
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 short sentences with the key guarantee (fail-closed) front-loaded and no filler. Dense and readable, though the middle sentence about claim fields could have been folded into the schema-adjacent guidance more cleanly.
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?
With no output schema and no annotations, the description does cover return values (confirmed/refuted/unverified plus a hash-bound report), which is the main thing an agent needs. It is still incomplete on the purpose of reported_hash and on failure modes, which matter for a fail-closed verifier.
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 0% across 2 parameters, so the description must compensate. It does well on "claims" by naming the four fields each entry carries (text, predicate, observed, expected), which the bare array-of-objects schema does not convey, but "reported_hash" is never mentioned at all despite being the non-obvious parameter.
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 ("claim verification") plus the fail-closed policy, which is enough to distinguish it from trust_stats or trust_check_injection. It stops short of naming any sibling explicitly, so an agent must infer that this is the claims-checking tool rather than the injection-checking one.
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?
"Fail-closed" hints at the posture on unverifiable input, but there is no explicit when-to-use guidance, no prerequisites, and no pointer to the sibling tools that cover adjacent jobs (trust_check_injection, trust_demo). The agent is left to infer the triggering context.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.