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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so safety is covered. The description adds genuinely useful non-obvious context: the response is the live headline total and deliberately lacks spendable/reserved breakdown, which prevents an agent from expecting sub-balances.

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 tight sentences, zero waste, with the core definition front-loaded and the output caveat second. Every sentence earns its place.

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 describing the return value, and it does so by naming the headline total and explicitly excluding spendable/reserved fields. Minor omissions (currency, staleness/freshness semantics) keep it short of a 5.

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, which is the baseline-4 case; there is nothing parameter-wise to explain. The description correctly refrains from inventing parameter semantics.

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: returns the live wallet total for this seat, and clarifies it matches the Home/Wallet headline figure. It does not name or contrast with the closest siblings (list_wallet_activity, list_wallet_refunds, get_usage), so it is clear but not sibling-differentiated.

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?

Usage is implied by 'the same headline as Home and Wallet' – an agent can infer this is the summary-balance call rather than a transaction listing. However, there is no explicit when-to-use guidance, no when-not-to-use, and no mention of the wallet activity/refund alternatives.

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