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

The description discloses key behavioral traits: it costs zero extraction credits, reserves no capacity, and requires account authorization. These are important operational details that go beyond what annotations would provide (and no annotations are present). It doesn't describe the exact response format, but for a zero-parameter read tool, the disclosed behavior is quite 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?

The description is compact and front-loaded: the first sentence states the core purpose, the second covers cost/resource behavior, and the third clarifies advisory nature. Every sentence adds value, and there is no redundancy or filler.

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 account status tool, the description is complete. It covers what the tool does, when to call it, what it costs, what it doesn't guarantee, and what authorization is needed. There is no output schema, but the description sufficiently describes the returned information.

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 provides no parameter semantics. The description compensates by explaining what the tool reads and what it returns, which is the relevant semantic content. A baseline of 4 is appropriate for a zero-parameter tool where the description explains the tool's purpose and output.

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 the tool's purpose: reading account credits and restrictions. It specifies the resource (own account) and the exact data returned (used, reserved, unreserved credits, reset date, restrictions). It distinguishes itself from siblings by focusing on account status rather than extraction or changes.

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?

The description provides explicit usage guidance: call before first or repeat work, not in a polling loop. It also clarifies that eligibility is advisory and that source/service/request-specific checks still apply, which helps the agent decide when to use this tool versus relying on it as a definitive gate.

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