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

Annotations already declare readOnlyHint=true, idempotentHint=true and destructiveHint=false, so the safety profile is covered without the description's help. The description adds the useful unit convention ('Amounts are in cents') but says nothing about auth scope, staleness, or how far back 'recent transactions' extends.

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?

A single sentence, front-loaded with the resource, followed by the returned fields and the unit convention. No filler and nothing that needs to be read twice.

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?

With no output schema, the description carries the burden of explaining the return shape, and it does list the key fields plus the currency unit. It stops short of describing transaction count, pagination, or ordering, which would help for the 'recent transactions' portion.

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 of 4 applies. The description correctly describes a no-argument read of the caller's own wallet, and the cents convention is the only semantic detail that could be conveyed.

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?

Names a specific verb and resource ('Get the user's prepaid advertising wallet') and enumerates the contents returned (balance, reserved funds, service fee, recent transactions). It does not distinguish itself from nearby siblings like get_billing_status or get_pricing, so an agent must infer which one is wanted.

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 contains no when-to-use guidance, no prerequisites, and does not name any alternative tool. Nothing tells the agent when this wallet view is preferable to get_billing_status or get_pricing.

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