Get account details

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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint and destructiveHint=false, so 'Read-only' in the description is largely redundant. The description does add useful context by listing exactly which account data is exposed (balance, billing day, status), which helps the agent judge whether the call answers its question. It does not cover rate limits, auth requirements, or failure modes.

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, no filler, and the returned-field list is front-loaded so an agent immediately knows what data it gets. The trailing 'Read-only' is the only near-redundant element.

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 payload, and it does so explicitly by naming every field. For a no-argument read tool this is fully sufficient to call correctly.

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 there are no parameter semantics to explain and the baseline is 4. Schema coverage is 100% and the description does not need to compensate.

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 ZapZap account') and enumerates the fields returned: name, email, balance, billing day, status. No sibling tool touches account-level data, so an agent can distinguish it from the instance/message/webhook/group 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?

Gives two concrete use cases: verifying that credentials work, and checking balance sufficiency before creating or renewing instances. That is clear positive guidance. There is no explicit when-not section, but no sibling competes for the same job, so the omission is minor.

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