Request a payment

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

Adds real behavior beyond the annotations: a Spend Guard policy layer evaluates the request, 'allowed' means the money is actually paid out, and the same idempotency key never pays twice. That reconciles the destructiveHint and idempotentHint flags into an operational story an agent can act on, rather than leaving them abstract.

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?

Six tight sentences, front-loaded with purpose and decision outcomes, then units, recipient constraint, idempotency, and the don't-circumvent rule. Every sentence carries an operational instruction and none duplicate structured fields verbatim.

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 money-moving mutation with no output schema, the description covers the decision outcomes, idempotency contract, and failure policy well. It does not say what a successful response contains (payment id, final status) that an agent would need to hand off to check_payment, which is the main remaining hole.

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 already 83%, so the baseline is 3, but the description adds meaning: minor-unit amounts with a concrete conversion example, the requirement that recipient be an allowed-list id sourced via get_my_limits, and the semantic tie between idempotency_key and the real-world obligation being paid. The currency enum's per-recipient applicability is left unaddressed, keeping it below a 5.

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 ('Ask to pay a known recipient by mobile money') and immediately describes the policy-decision outcome space (allowed/held/denied). It also points to the sibling that owns the recipient allow-list (get_my_limits), so an agent can distinguish this from get_my_limits and check_payment without opening a schema.

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?

Gives strong when/when-not guidance: always pass an idempotency_key keyed to the underlying obligation, reuse it on retry, and on held/denied do not retry, split the amount, or switch recipient — tell the user instead. The gap is that it never states its relationship to the sibling check_payment (e.g., use that to poll status), so the alternative-tool routing is only partly covered.

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