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

Beyond the annotations (readOnly=false, destructive=false, idempotent=true), the description discloses that invalid transitions are rejected, that ISSUED from SENT is a mistake-undo that never un-issues an invoice, that SENT records sent_at, and that fiscal guardrails apply. This adds significant behavioral context without contradicting the annotations.

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 well-organized with a clear lead sentence, bulleted transition rules, a 'Not set here' callout, the endpoint, and a warning. Every sentence earns its place and the most important constraints are front-loaded.

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 state-machine-sensitive status change, the description provides the endpoint, valid transitions, exclusions, guardrails reference, and a pointer to detailed docs. It is sufficiently complete for an agent to call the tool correctly, even without an 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 already documents each parameter well (status enum, sent_at, payment_date, payment_method, company_id semantics), so the description doesn't need to repeat them. It adds value by mapping status meanings to allowed transitions and clarifying that issuing/voiding are out of scope. Slight deduction because it doesn't explicitly describe the body fields' conditional behavior, but the schema covers that.

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: 'Sets the commercial status of an invoice,' and immediately distinguishes itself from fiscal operations by stating 'issuing and voiding are fiscal acts with their own operations' and naming the dedicated endpoints. This clearly separates it from sibling tools like beel_issue_invoice and beel_void_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?

It explicitly enumerates the only valid transitions (PAID, SENT, ISSUED), states that anything else is rejected, and tells the agent what is NOT handled here (issue/void). It also directs the agent to the guardrails resource and beel_docs_search for exhaustive rules, giving clear when-to-use and when-not-to-use guidance.

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