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

The description adds meaningful behavioral context beyond the readOnlyHint=true and destructiveHint=false annotations: 'Free, spends no credits.' This is valuable for an agent deciding whether to call the tool, though it does not disclose other potential details like rate limits or caching.

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 a single, efficient sentence that front-loads the core purpose before adding the cost and usage notes. No filler or redundancy; every clause adds relevant information.

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?

With an output schema present and zero parameters, the description covers all necessary context: what is returned (plan and credits), the cost implication, and the recommended use case. Nothing an agent needs to call this tool correctly is missing.

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 already fully documents everything. The description does not need to add parameter details; the baseline for a zero-parameter tool applies here.

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 names a specific verb ('Get') and explicit resources ('plan and remaining credits') for a named entity ('1Lookup organization'). This clearly differentiates the tool from its siblings, which are all verification/lookup operations rather than account inspection.

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?

'Call before a large run' provides a clear, actionable trigger for using the tool. It does not explicitly name alternatives, but the account-focused purpose and mention of cost make it unambiguous when to invoke this tool versus the sibling verification tools.

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