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

The annotations already establish a safe read-only, idempotent, closed-world operation. The description adds substantial behavioral context beyond that: it defines disabled/internal/exempt as no-charge states with null fields, explains that exhausted means the balance is spent, and clarifies that paid automated analysis is charged by model usage rather than a fixed price.

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 front-loaded with the return semantics and contains no filler. The opening sentence is long and dense with multiple clauses, but every sentence contributes useful meaning about statuses or charging behavior.

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?

Given zero parameters, rich annotations, and an output schema, the description is complete enough. It explains the key status semantics and cost model that an agent would need to interpret the response correctly.

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 takes no parameters, so the baseline is 4. The description correctly adds no parameter guidance because there is nothing to clarify.

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 read operation: it returns the connected organisation's credit-charging status, balance, refusal-at-zero behavior, and per-operation costs. This is unambiguous and immediately distinguishes get_credits from every sibling tool.

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?

Usage is implied by the returned cost information for patent import and public patent search, but the description never explicitly says when to call this tool, such as before a paid operation. There are no alternatives to route between, but the when-to-use guidance remains implicit rather than stated.

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