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

With no annotations provided, the description fully carries the behavioral disclosure burden. It discloses that the tool returns an Ed25519-signed fact with IN_SCOPE/OUT_OF_SCOPE/UNDECLARED verdicts, bound to nonce+request hash to prevent replay/reuse, and emphasizes it is never a verdict on intent. This is rich, non-obvious behavior.

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 description is compact and well-structured. It opens with the core purpose, then explains the signed output and anti-replay guarantee, and finishes with the philosophical distinction and verification pointer. Every sentence adds value; no fluff.

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 the complexity of permission checking and no output schema, the description covers the essential outcomes (signed verdicts), binding mechanism, and verification path. It could go further by explaining what to do with the signed fact or edge cases, but the current information is sufficiently complete for safe invocation.

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 input schema provides 100% coverage with descriptions for all parameters. The tool description only summarizes the grant fields (allowed action, merchant/domain, etc.) without adding meaning beyond what the schema already documents. Baseline of 3 is appropriate.

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 checks whether an agent's proposed action stays inside its declared permission grant, enumerating the grant dimensions (allowed action, merchant/domain, spend cap, budgets, etc.). It distinguishes itself from siblings by emphasizing it returns signed conformance facts, not judgments on intent.

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 notes this is a mechanical conformance check and explicitly contrasts with 'a verdict on intent,' giving a sense of when to use it. It also points to a related tool (onyx_attestation_verify) for verification, but does not explicitly name alternative time-to-use scenarios or exclusions.

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