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

With no annotations, the description carries full responsibility for exposing behavioral traits. It discloses that authentication is required and that the tool reports how many pre-signed authorizations remain, but it does not explicitly state that it is read-only or whether viewing the rule consumes authorizations. This leaves ambiguity about potential side effects.

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 two concise sentences with no filler. It front-loads the resource and includes a separate note about authentication. Every word serves a purpose.

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 simple zero-parameter getter with no output schema, the description provides the key information: what it returns and that auth is needed. It is sufficient for invoking the tool, though it could enrich the context by explaining what 'auto-topup rule' means or describing the response format, but this is not critical given the tool's simplicity.

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, so the schema is completely covered by default. The description adds no parameter-specific meaning, but none is needed. The baseline of 4 for zero parameters 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 clearly identifies the resource (auto-topup rule and remaining pre-signed authorizations) and implies a retrieval operation, but uses a noun phrase ('The auto-topup rule...') rather than an explicit verb like 'Gets' or 'Fetches.' It does not distinguish from siblings like set_auto_topup, but the tool name and context make the purpose clear.

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 only usage-related information is 'Auth required,' which is a prerequisite rather than guidance on when to use this tool versus alternatives. There is no mention of when to call get_auto_topup instead of set_auto_topup or remove_auto_topup, or what scenarios benefit from checking the rule and authorization count.

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