The org's unbilled enterprise post-pay liability (to put on a Xero invoice).

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

Annotations already declare readOnlyHint=true (safe read operation), destructiveHint=false, and idempotentHint=false. The description adds no additional behavioral context beyond the annotations. It does not contradict annotations, but it also does not disclose any further traits such as data freshness or authentication requirements.

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 a single sentence, which is concise. However, it is identical to the title and lacks informative content. Conciseness is good but structure does not add value; it's just a label.

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 no output schema and no parameter descriptions, the description is incomplete. It does not specify the meaning of 'period' or the required 'organization_id'. For an enterprise billing tool, these are likely critical for correct usage. The description fails to provide a comprehensive understanding.

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 0%, so the description should compensate by explaining the parameters. However, the description does not mention any of the three parameters (x-api-key, organization_id, period). It provides no information on what values are expected or how they should be used. This is a critical gap.

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?

Tautological: description restates name/title.

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 provides no guidance on when to use this tool versus alternatives. There is no mention of prerequisites, contexts, or when not to use it. Sibling billing tools exist (e.g., billing.invoices.list, billing.credits.balance) but the description does not differentiate from them.

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