create_invoice_from_time

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

The description discloses that the invoice is built from tracked time entries and scoped to a project, which is useful behavioral context. However, with no annotations, it does not clarify side effects (e.g., whether time entries become marked as invoiced), the invoice status, or required permissions, leaving some ambiguity for a mutation tool.

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 filler or redundant detail. It communicates the core action, source, and scope efficiently.

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 that the tool has four parameters and no output schema, the description covers the primary purpose but leaves out side effects and potentially helpful exclusions (e.g., how invoiced time entries are handled). The schema fills parameter details, but the description alone is not fully complete for an agent needing decision-grade context.

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 input schema already provides descriptions for all four parameters, including date ranges and UUIDs, so the description does not need to repeat them. The tool description adds the high-level 'time entries' concept but does not elaborate on relationships or formatting, so the baseline 3 is appropriate.

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 ('Create'), a clear resource ('invoice'), and a distinctive source ('tracked time entries'), making it easy to understand exactly what the tool does. It also differentiates from the sibling create_invoice by specifying that entries are derived from time tracking.

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 phrase 'from tracked time entries for a project' provides a clear contextual clue for when to use the tool, implying a time-billing scenario. However, it does not explicitly mention alternatives or state when not to use it, such as contrasting with create_invoice for manual invoices.

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