ping

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

Adds context the annotations do not carry: it performs an end-to-end check against the backend (validating the key, not just network reachability) and costs 0 credits. Annotations already cover safety (readOnly, non-destructive), so this added cost and validation-scope information is meaningful. No mention of failure output or rate limits, keeping it below a 5.

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 the usage trigger, then the mechanism, then the cost. No waste.

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 parameterless diagnostic with no output schema and full annotation coverage, the description gives an agent everything needed to decide to call it. Only gap is what a success/failure response looks like, which is minor 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?

Zero parameters, so baseline is 4; the description correctly implies no arguments are needed to invoke it. Nothing further is required.

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+resource: 'Tests API connectivity end-to-end by verifying the API key against the backend.' This clearly separates it from the data-retrieval siblings (organic_serp, get_balance, etc.), which all return local marketing data rather than a health check.

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?

'Use when diagnosing connection or authentication issues' gives an explicit trigger condition. No when-not guidance or named alternative is given, but none of the siblings overlap enough to require routing instructions.

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