Account resource usage

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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so safety is covered. The description adds genuinely non-obvious behavioral context: the breakdown of what is measured (disk, bandwidth, databases, email accounts, domains) and the sentinel convention that "a null maximum means unlimited", which an agent could easily misread as zero or missing data.

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 short sentences, zero filler. The scope statement comes first and the null-maximum caveat follows immediately, which is the right ordering for an agent skimming before a call.

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?

With no output schema, the description carries responsibility for return semantics; it does list the measured resources and explains null maximums, which is enough to interpret results. It does not describe the response shape (e.g., used-vs-maximum pairing) or whether limits come from the package, leaving a modest gap.

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 description coverage is 100% and the single parameter is fully documented in the schema, including the lowercase pattern and a pointer to whm_list_domains for discovering the username. The description adds nothing about the parameter, which is acceptable at this coverage level but is the baseline rather than a contribution.

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?

"Get one account's usage against its limits" names a specific verb and resource and scopes it to a single account, which implicitly separates it from server-wide siblings like whm_disk_usage and whm_bandwidth_usage. It stops short of naming those alternatives explicitly, so the differentiation must be inferred from the word "one account's".

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 only implied: the scoping to a single account suggests this is the per-account counterpart to the aggregate disk/bandwidth tools, but there is no explicit "use this when... use X instead" guidance and no statement of prerequisites such as needing an existing account.

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