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

Annotations indicate a non-read-only, non-idempotent operation. The description adds meaningful behavioral context: it is a permission-request step that generates an Intent Mandate token and involves the user. This goes beyond the annotation flags without contradicting them.

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 short, front-loaded sentences deliver the core purpose, user interaction, and usage timing without any filler. Every sentence earns its place and the message is immediately actionable.

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 presence of a full output schema, detailed parameter descriptions, and clear annotations, the description adequately covers the tool's role and timing. It might have explained post-authorization behavior, but the output schema likely handles that, so the description is sufficiently complete for selection and 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 schema already provides 100% parameter coverage, describing maxPerTxCents and maxMonthlySpendCents in detail. The description mentions 'spending limits' but does not add further semantic nuance beyond what the schema already documents, so the baseline score 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's purpose: setting up agent spending limits and requesting user permission to spend money, culminating in an Intent Mandate token. It distinguishes itself from sibling payment tools by explicitly framing it as a pre-payment authorization step.

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 guidance 'Use this BEFORE making a payment' directly indicates when to invoke the tool relative to payment. It does not explicitly name alternative tools or when not to use it, but the timing instruction is clear and actionable.

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