get_credit_usage

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It usefully explains that this is a live, authoritative view of account capabilities, and that area limits and endpoint access vary by plan. However, it does not explicitly state the operation is read-only/no side effects, nor does it mention any authentication requirements or response format nuances.

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 compact sentences deliver all necessary information with no filler. The first sentence immediately states what the tool returns, and the second adds authoritative context about plan-dependent limits. Every sentence earns its place.

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, no-output-schema tool with no annotations, the description is complete enough for an agent to know exactly what this tool provides and why it should consult it. It covers the return contents (plan, balance, per-endpoint usage), the authority of the data, and the variability of limits by plan.

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 are no parameter semantics to document. The description instead focuses on what the tool returns, which is appropriate. This matches the baseline for zero-parameter tools.

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 states a specific resource (account plan, credit balance, per-endpoint usage breakdown) and clarifies this tool is the authoritative source for key capabilities. This distinguishes it from siblings like get_storage_info or submit_heatmap, which clearly serve different purposes.

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 clearly indicates when to use this tool: whenever you need authoritative plan limits, credit balance, or endpoint access details. It explicitly says these are 'not assumed anywhere in this server', giving the agent a strong signal to call this before making assumptions. It does not name specific alternative tools or provide explicit when-not-to-use guidance, so it stops short of a 5.

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