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

Annotations only supply destructiveHint=true; the description carries the rest and does so well: draft saves with no number, draft=false consumes the next series number, cannot be deleted or edited through this server, can only be cancelled or reversed (storno), and may be transmitted to ANAF depending on e-Factura setup. That is exactly the irreversibility/authorization context an agent needs before a write.

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?

A single dense paragraph that front-loads purpose, then the draft/issue decision, then the return payload, then the endpoint. Every sentence carries decision-relevant information; nothing is redundant with the schema.

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?

No output schema exists, so the description usefully enumerates the return fields (series, number, documentId, documentUrl needing login, documentViewUrl as a public PDF). Combined with the mutation semantics and the sibling list lookups it references, nothing an agent needs to call this correctly is missing.

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 100%, so every parameter (including the nested client and products objects) is already documented in the schema and the baseline is 3. The description restates the draft flag's meaning and names sibling lookups for series/taxes, but adds no per-parameter syntax or format 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?

States a specific verb, resource and content ("Create an invoice for a client with product/service lines") and immediately frames the two operating modes. An agent can distinguish it from smartbill_create_invoice_from_estimate and smartbill_create_estimate without opening the schema.

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?

Explicitly says when to keep the default draft (review in SmartBill Cloud) and when to pass draft=false (user explicitly wants it issued now), plus a required confirm-with-user step. It does not, however, route the agent between this tool and the sibling smartbill_create_invoice_from_estimate.

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