get_server_invoices

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety is covered. The description adds only the upstream API mapping (whmcs/get_related_invoices), which does not disclose pagination, ordering, result shape, or what counts as 'related'. Nothing behavioral beyond the annotations.

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 economical sentence with no waste, but it is arguably too terse: one short clause plus a parenthetical endpoint reference for a tool that could carry more routing detail.

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 one-parameter read tool with no output schema this is minimally viable, but it omits what is returned (count, fields, pagination) and how it differs from get_invoices/get_invoice in a large billing sibling group.

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?

Schema coverage is 100% and the single parameter 'id' is documented as 'Server ID'. The description's 'specific server' phrasing reinforces this but adds no syntax or format detail beyond the schema, so baseline 3 applies.

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?

States a specific resource (invoices) scoped to a specific server, which distinguishes it from the sibling get_invoices (all invoices) and get_invoice (single invoice). It lacks an explicit verb but the noun phrase plus scope is unambiguous enough to route correctly.

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?

No guidance on when to use this versus get_invoices or get_invoice, nor any prerequisite or context. The scoping phrase 'related to a specific server' hints at the use case but leaves the agent to infer the alternative's condition.

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