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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered and the description only needs to add context. It does so by enumerating the concrete data domains returned (allowance, rollover, top-ups, reset date, Lite mode), which tells the agent this is a snapshot read rather than a configurable query. It stops short of noting freshness, account/auth scope, or response shape.

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 front-loaded sentence with the resource named first and the returned fields parenthesized. Zero filler, nothing repeated from the title, and the highest-value information (what the balance breakdown contains) comes before the secondary Lite mode detail.

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?

There is no output schema, so the description absorbs the burden of describing return values — and it does, listing the four credit components plus Lite mode status. What is missing is minor but real: whether the numbers are per-seat or org-wide units, and whether Lite mode is a boolean flag or an object.

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 per the baseline there is nothing for the description to disambiguate. It correctly avoids inventing parameter talk and spends its words on output semantics instead.

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 (Get) plus a precisely scoped resource: the organization's AI credit balance with the sub-components named (monthly allowance, rollover, bonus/top-ups, reset date) and Lite mode status. No sibling tool in the list touches account usage or billing, so the agent can distinguish this from the post/brand tools at a glance.

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 says what the tool returns but never says when to call it — no mention of checking credits before generation, pre-flight quota validation, or troubleshooting blocked requests. There are no exclusions or alternatives offered, though in this case no sibling is a plausible substitute.

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