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

Annotations already declare this a safe, non-destructive, closed-world read, so the description carries a lighter burden. It usefully discloses the dual-unit output and that a zero balance includes an explanatory line, but says nothing about freshness, caching, or when the zero reason is absent — and the existing output schema already documents the 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 key unit conversion, so nothing essential is buried. The trailing clause about the zero-balance line is slightly awkward but still 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 parameters, an output schema, and full annotation coverage, the description only needed to explain what the number means and the edge case at zero — both of which it does. The missing piece is disambiguation from sibling read tools.

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 is no semantic gap to close and the baseline of 4 applies. The description correctly implies no filtering or scoping is possible.

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 names the resource precisely ("Money available for running Nods") and pins down units and representation, so an agent knows exactly what is read. It stops short of a clean verb+resource statement and never distinguishes this from siblings like get_account or get_usage.

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?

There is no guidance on when to call this versus get_account or get_usage, which sit in the same account/balance neighborhood. The agent must infer usage from the wording alone.

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