Evaluate a proposed agent action before execution

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations supplied, the description carries the full burden and does well: it discloses the three possible verdicts (allow, hold, deny), that hold requires human approval, and — importantly — that every call is persisted to a SHA-256 hash-chained audit log, which is a real side effect an agent must anticipate. It stops short of stating auth requirements, latency, or whether evaluations are rate-limited.

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, front-loaded with the action and its timing constraint, followed by the return values and then the audit side effect. No filler or restatement of the title.

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, so the description usefully names what comes back — verdict, risk score, fired signals, reasons — and the persistence behavior. Given the absence of annotations and the 100% schema coverage on inputs, the only real gap is operational context (permissions, failure modes, what a hold verdict requires of the caller procedurally).

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 all four parameters (action, context, history, requestedActions) are already documented in the schema, including the rationale for escalation scoring and independent gating of consequential actions. The description adds no parameter-level meaning beyond that, so the baseline of 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?

The description gives a specific verb and resource ('Evaluate a proposed AI-agent action against Sentinel policy') plus the decisive scoping detail 'BEFORE it executes,' which distinguishes it from siblings like sentinel_explain_policy or sentinel_audit_status that inspect policy or logs rather than gate an action.

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 timing condition 'BEFORE it executes' is a clear usage cue, so an agent knows this is a pre-flight gate rather than a post-hoc audit check. However, it never names alternatives or exclusions — e.g., that sentinel_explain_policy should be used to understand a deny verdict, or when to skip evaluation.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.