beel_get_usage

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

Annotations already mark this as read-only and idempotent; the description adds valuable behavioral specifics beyond that: billable counting treats every provisioned account equally including empty/unclaimed ones, usage belongs to the provisioner and not the provisioned account, wrong account IDs return 404, and manage_accounts is required. This fully discloses error behavior, scope, and authorization nuance.

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 compact and front-loaded with the core answer. Bullets separate the billable unit, account_id semantics, and entitlement without redundancy, and the endpoint line is a useful concrete reference. No sentence is wasted.

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 a single parameter, full schema coverage, rich annotations, and low complexity, this description leaves no critical gap. It explains what is returned, how the count is calculated, the required permission, and the failure mode for invalid account IDs. No output schema is present, but the return value is simple enough that the description suffices.

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 schema already fully describes account_id, so the baseline is 3. The description adds meaning beyond the schema by explaining that account_id must be your own provisioner account, that usage is not per provisioned account, and that other IDs will 404. That extra semantic context justifies a score above baseline.

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 opens with a specific verb and resource: 'Returns how many accounts you have provisioned and the billable count that follows from them.' It clearly distinguishes this from sibling get_* tools by focusing on usage/billing counts rather than account details, invoices, or other resources.

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 gives clear context for when to call this tool: when you need billable account counts for an offline B2B invoice. It also provides exclusion guidance by stating that only your own account_id works and any other id returns 404, plus the required manage_accounts entitlement. It stops short of naming alternative sibling tools, so it doesn't reach the highest bar.

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