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

Beyond the readOnlyHint and destructiveHint annotations, the description adds the important behavioral guarantee that it does not start a scan and does not spend credits. That is useful context for a credit-checking tool, though it does not describe return format or any authentication expectations.

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 purpose is front-loaded in the first sentence, and the second sentence adds a useful negative constraint without wasting words. The first sentence is dense with parenthetical duration details, but those details are relevant and not clearly removable.

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, read-only tool with rich annotations and no output schema, the description covers what the tool reports and what it does not do. It could be slightly more complete by clarifying its relationship to sibling credit/wallet tools, but no critical gap prevents correct invocation.

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 no parameters, so parameter semantics are not a meaningful source of ambiguity. The baseline for zero-parameter tools is 4, and the description does not need to explain parameter behavior.

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 states that it shows current file and live-site credits, protection durations, and authorization scopes, which is a specific resource-plus-information purpose. It distinguishes itself from scan-starting tools by saying it does not start a scan, but it does not explicitly differentiate itself from close siblings such as vulkill_credit_usage or vulkill_wallet_status.

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?

It gives an implied usage context by stating that it does not start scans or consume credits, which helps an agent understand when it is safe to use. However, it does not explicitly say when to use this tool versus the credit_usage or wallet_status siblings, so alternative selection is left to inference.

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