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

Annotations already declare readOnlyHint=true and destructiveHint=false, so safety is covered. The description adds meaningful behavioral context beyond that: no order is created, nothing is charged, any key can use it, and it is free. These are exactly the traits an agent needs before invoking it, though auth requirements are only stated loosely as 'any key.'

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?

Three short sentences, front-loaded with what is returned, then the no-charge guarantee, then accessibility notes. No filler or repetition.

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 tool, the description covers purpose, return value (link and balance), cost behavior, and key accessibility. With no output schema, the description appropriately names the two returned items. Could be slightly stronger by noting pagination or rate limits, but none are implied for this simple lookup.

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 schema-level parameter documentation to compensate for. The description correctly conveys that no input is needed, which is the right baseline for a 0-param tool.

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 (returns) and two concrete resources: the console top-up page link and the current balance. This is distinct from siblings like everyinfra_billing (likely invoice/payment data) and everyinfra_account, so an agent can route correctly without opening the schema.

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?

Explicitly says the account owner pays in the console and this tool creates no order and charges nothing, which tells the agent when NOT to expect a transaction. It doesn't name a specific alternative sibling for balance queries, but the use context is clear.

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