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

The description explicitly calls it a 'read-only view', which reinforces the readOnlyHint and idempotentHint annotations. It adds context that this opens a widget, which is useful beyond the structured data. No contradictions exist.

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 that efficiently communicates the action, resource, and accepted inputs. No verbose or redundant content.

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 the simplicity of a read-only widget opener, the description covers the core behavior, the completed-cobro prerequisite, and the accepted identifiers. Combined with the annotations, this is sufficiently complete for an agent to select and invoke the tool. Missing explicit return/display details, but no output schema is provided.

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 describes all three parameters individually with 100% coverage. The description merely lists the parameter names without adding new semantic detail (e.g., when to use each identifier), so it doesn't improve on the schema. 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 clearly states the action (opens a widget), the resource (comprobante + envío / delivery receipt), and the scope (for a completed cobro). It distinguishes itself from sibling tools like open_cobro_status or open_sale_confirm by focusing on the receipt view specifically.

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 'for a completed cobro' gives clear context on when to use, and the three accepted identifiers show flexibility. However, it doesn't explicitly name alternatives or state when not to use, so it doesn't fully meet the 'explicit when/when-not' bar.

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