get_credit_history

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds only the upstream endpoint hint (whmcs/getcredits); it says nothing about time range, pagination, or whether the id is a client or server identifier, which is the main behavioral ambiguity here.

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?

A single front-loaded clause with the endpoint reference tucked in parentheses; no wasted sentences. It is efficient, though the endpoint detail is of marginal value to an agent.

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 simple one-parameter read tool with no output schema and read-only annotations, this is minimally adequate, but it omits the return shape (a list of movements) and any temporal/pagination behavior, leaving the agent to discover those at call time.

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?

One parameter with 100% schema description coverage, so the schema already documents 'id' as Server ID. The description adds no syntax or interpretation beyond that, which is the expected baseline when the schema does the work.

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 resource (credit balance movement) and enumerates the two kinds of entries it reports (additions and deductions), which is more than a restatement of the name. It does not, however, differentiate itself from adjacent billing siblings such as get_transactions, apply_credit, or get_server_billing_data.

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?

There is no statement of when to call this versus an alternative, no prerequisite (e.g. which id is expected), and no scope caveat. The agent must infer usage purely from the name.

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