Create invoice

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

Goes well beyond the annotations by disclosing default dates (now and now+7 days), the email queueing side effect via Blesta's cron, the draft/unissued behavior, and the return value (numeric invoice ID and stored invoice). This is substantial behavioral context for a non-read-only 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?

Three sentences, with the core action front-loaded and every sentence contributing either a default, a side effect, or the return value. No filler or redundancy.

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?

Despite having 9 parameters and no output schema, the description covers the essential creation context, defaults, side-effect toggles, and return payload. The input schema handles field-level formats, so nothing critical is missing for an agent to invoke this correctly.

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 coverage is 100%, so the baseline is 3. The description adds meaningful semantics for key parameters: deliver_by_email queues cron-based email, draft creates an unissued invoice, and date fields have explicit defaults. This exceeds what the schema alone provides.

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?

States a specific action ('Create a new invoice for a client with one or more line items') and names the underlying operation ('Wraps Invoices.add'). It is clearly distinguishable from sibling tools like update_invoice, send_invoice, and get_invoice.

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 makes the primary use case unambiguous and clarifies mode choices (draft vs issued, deliver_by_email vs not). It does not explicitly name alternatives or say 'use update_invoice for existing invoices,' but the creation context is clear enough that an agent can infer when to call it.

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