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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description adds two things not in structured data: the required `payments:read` scope (a real auth prerequisite) and the handling rule that free-text appears in `untrusted_fields` and must be shown, not executed — useful prompt-injection guidance even though no output schema exists.

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?

Two sentences, zero waste, with the core action front-loaded ahead of the auth requirement and the output-handling caveat. Nothing repeats what the annotations or schema already state.

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 parameterless read with annotations and no output schema, the description covers auth and output trust handling, which is more than most. However, it never says what the "totals" aggregate over — time window, currency, or whether it is lifetime versus current period — so an agent cannot describe the result meaningfully to a user.

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 tool takes zero parameters, so the baseline is 4. The description correctly says nothing about inputs, and nothing about inputs is needed.

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?

"Get my payout totals" names a resource and an aggregate shape, which distinguishes it weakly from list-style siblings like list_payments or list_transfers. But it is a near-verbatim restatement of the title and never distinguishes it from get_payout_setup, get_account_billing, or get_payment, all of which a caller could plausibly reach for.

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?

There is no explicit when-to-use or when-not-to-use guidance, and no named alternative. The only routing signal is the implied prerequisite of the `payments:read` scope, which tells the agent a condition for success but not when this tool is the right choice over get_payout_setup or get_account_billing.

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