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

With no annotations provided, the description carries the full burden of behavioral disclosure. It explains the return value semantics (sats available for certifying purchases), the consequence of a zero balance (top-ups cannot be certified), and a clarifying trait (operator's own funding, free). It does not explicitly state the operation is read-only, but 'Check' implies non-mutating, and no side effects are mentioned; a 4 is warranted for covering the key behavioral aspects.

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?

The description is four sentences, each earning its place: purpose, return value, consequence+next step, and ownership distinction. It is front-loaded with the core action and avoids redundancy or filler. The structure is logical and compact.

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?

For a zero-parameter tool with an output schema present, the description covers everything an agent needs: what the value represents, what happens when it is zero, the required follow-up action, and a caveat to prevent misuse. It is complete for correct invocation and decision-making.

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 has zero parameters and the input schema is empty, so there is no parameter ambiguity to resolve. Schema description coverage is trivially 100%. The description adds no parameter details, but none are needed, so the baseline 4 for zero-parameter tools applies.

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 opens with a specific verb and resource: 'Check this operator's tax balance at the Authority.' It clearly differentiates this from the sibling goodearth_check_balance by stating 'This is the operator's own funding — not a patron balance.' This leaves no ambiguity about which balance is being checked.

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 provides clear context for when to use the tool: it returns the sats available for certifying patron credit purchases, and states that when the balance reaches zero, the operator must call purchase_credits on the Authority. It also explicitly warns against confusing this with a patron balance. However, it does not explicitly name alternative check tools like goodearth_check_balance or state 'use this instead of X,' so it stops short of full exclusion guidance.

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