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

Annotations already flag destructive=true and idempotent=false, but the description adds substantial context beyond them: no draft state, no post-issue editing, irreversible number consumption, cancellation-only recovery, optional ANAF e-Factura/SPV transmission, and no client e-mail. These are exactly the consequences an agent needs before firing an irreversible fiscal 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?

It is a dense single paragraph, but it is front-loaded with the action and irreversibility, followed by prerequisites and behavioral caveats in a sensible order. Nearly every sentence earns its place, with only mild redundancy between the narrative and the schema's own notes.

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?

For a 22-parameter, nested, irreversible write with no output schema, the description covers the critical safety context (confirmation, idempotency, irreversibility, retry handling, e-mail behavior) that the schema cannot express. It does not describe what a successful response contains or how errors are surfaced, but the essentials for correct invocation are present.

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 the schema already documents all 22 parameters in depth. The description restates a few high-signal ones (confirm, idempotency_key, reference_document, collect, delivery_date) but adds no syntax, format, or constraint detail beyond what the schema carries. Baseline 3 is appropriate when the schema does the heavy lifting.

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 opens with a specific verb and resource ("ISSUE a real INVOICE") and immediately characterizes it as a legal fiscal document that consumes the next number in the series. It implicitly distinguishes itself from sibling document tools (proforma creation via reference_document, cancellation, separate collection) so an agent knows this is the finalizing step, not a draft.

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?

It states concrete prerequisites (confirm:true, idempotency_key, explicit user approval) and a clear safety rule (not retried; inspect Oblio before repeating), plus that no e-mail is sent. It implies the cancellation path and the optional collect step, but it never names the sibling tools (oblio_cancel_document, oblio_collect_invoice) as the alternatives for those flows, so it falls short of a full when-to-use/when-not matrix.

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