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

Annotations already flag this as a non-readOnly, open-world, non-idempotent, non-destructive operation. The description adds genuinely useful behavior beyond them: it emits a decision_id consumed by downstream handshake tools, and it discloses the billing rule that "a deny is not charged." It stops short of explaining the non-idempotent side effect (what calling twice does).

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 tight sentences with zero filler, and the core allow/deny purpose is front-loaded before the return value and billing caveat. Nothing needs trimming.

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?

An output schema exists, so return values needn't be enumerated, and the description still notes decision_id for chaining. Parameter semantics and the deny billing rule are covered for a simple two-param tool; only format-level parameter detail and any auth/rate context are absent.

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 0%, so the description carries the burden, and it does name the semantics of both parameters: one market and one actor class per call. However it gives no format, vocabulary, or validation guidance (e.g., what identifiers markets or actor classes take), so ambiguity remains at invocation time.

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+resource: gate a transaction with an allow/deny decision scoped to one market and one actor class. It's clearly a pre-handshake decision point. It doesn't, however, distinguish itself from the similar-sounding sibling check_eligibility, leaving ambiguity about which gating tool to pick.

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 gate before a handshake" implies the ordering context, and naming handshake tools as the consumers of the returned decision_id suggests when it's needed. But no alternative is named or excluded, and check_eligibility is a close sibling that the description never contrasts against.

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