get_usage

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

With no annotations, the description carries the full burden. It correctly implies this is a read-only check and explains the consequence of exceeding quota, but it does not explicitly state that this tool has no side effects, does not consume quota, or what the response structure looks like. Some behavioral detail is present, but not complete.

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?

Two sentences, front-loaded with the core purpose, followed by a clear use-case and rationale. Every sentence earns its place and there is no redundant 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?

For a no-parameter tool, the description covers the key returned information: plan, monthly sent count, and remaining allowance. It could explicitly mention response formatting or units, but this is not critical given the simple nature of the tool and the absence of parameters.

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 there is no parameter semantic burden. The description appropriately focuses on what data is returned rather than input details.

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 what the tool reports: the workspace's plan, emails sent this month, and remaining quota. It lacks an explicit verb like 'retrieve' or 'get', but the meaning is unambiguous and distinct from all sibling tools.

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 a concrete usage context: check before a large batch send, because exceeding the included allowance without overage causes the whole send to be refused. It does not mention alternatives or explicitly say when not to use it, but the guidance is practical and sufficient for this simple read-only tool.

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