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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world, so the safety profile is covered. The description adds genuine value beyond that by enumerating the returned payload — lines, totals, frozen seller block, applied vs. open amounts, and a shareable doc link — which matters since there is no output schema. It stops short of noting failure behavior for an unknown invoice_id.

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?

One compact sentence with no filler; the substantive content (document contents) is front-loaded. It is a fragment rather than a sentence, which costs a little clarity but wastes no words.

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 one-parameter read tool with full annotation coverage, the description covers what is returned well enough to replace a missing output schema. What it omits — that it is a lookup by ID and what happens on a missing or voided invoice — are small but real gaps.

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% and the single invoice_id parameter carries an example format ("INV-0001"). The description adds nothing about the parameter, so the baseline 3 applies — the schema does all the work.

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 whole document" implies a full-detail retrieval of an invoice, and the listed contents (lines, totals, seller block) make the resource recognizable. But there is no explicit verb (fetch/get/return) and no differentiation from close siblings like solo_get_document or o2c_get_invoice, so an agent must infer from the name alone.

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 gives no guidance on when to call this versus solo_get_document, solo_outstanding, or o2c_get_invoice. It also never states the prerequisite that a valid invoice_id must exist, so selection depends entirely on the tool name.

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