inspect_client_billing_state

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds the classification categories, which hints at the output, but does not disclose any side effects, return format, or constraints beyond that. This is acceptable but not rich.

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, front-loaded with the action verb, and contains no filler. Every word contributes to the meaning.

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 three parameters, no output schema, and 0% parameter coverage, the description is too sparse. It does not explain how to select months, the role of client_id or invoice_key, or what the classification result looks like. The categories provide some context but not enough for an agent to confidently invoke the tool.

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 must compensate. It adds the qualifier 'live FYI months' for the months parameter, but does not explain client_id or invoice_key, leaving two parameters completely undocumented. The description provides only minimal added meaning beyond the schema.

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 uses a specific verb 'Classify' and clearly specifies the resource ('selected live FYI months') and the output categories (unsplit, split, partially allocated, ambiguous, missing, inconsistent). This distinguishes it from sibling tools like prepare_interim_split or plan_client_billing, which suggest mutating or planning actions rather than inspection.

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 implies usage by stating what the tool does, but provides no explicit when-to-use or when-not-to-use guidance, and does not mention alternative tools. The phrase 'selected live FYI months' gives some context but no exclusions or scenarios.

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