books_mark_purchase_order_as_billed

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

No annotations are present, so the description carries the full burden. It only says 'Mark a purchase order as billed' without disclosing side effects, permissions, reversibility, or what happens to the purchase order status. This is under-specified for a mutating action.

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, front-loaded sentence with no unnecessary words. It is maximally concise while conveying the core action.

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 the complex domain of purchase orders (with many sibling lifecycle tools), the description is too thin. It does not explain what 'billed' means, whether this triggers related actions (e.g., bill creation), or any prerequisites. This is insufficient for a mutating tool with no output schema.

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 has 0% description coverage; the description does not mention the 'purchase_order_id' parameter. While the parameter name is self-explanatory, the description adds no meaning, constraints, or format details, leaving the agent to infer from the name alone.

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 clearly states the action: 'Mark a purchase order as billed', which is a specific verb+resource. It distinguishes this tool from siblings like mark as open, cancel, or approve by indicating a specific state change.

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 is provided on when to use this tool or what conditions should be met (e.g., purchase order must be open). It does not compare to alternatives or mention exclusions, leaving the agent without context for selection.

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