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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the closing "Read-only." is largely redundant. What does add value is the disclosure of the returned payload — header fields (number, date, status, client, totals, currency) plus every line (item, SKU, quantity, unit, price, line total, shipped quantity) — telling the agent this is a full-detail fetch, not a summary.

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 scope statement and read-only flag are front-loaded and the sample phrasings are compact and useful for matching. The long mid-sentence field enumeration ("number, date, status, client, total … with tax … every line — item, SKU …") is bulky but each item earns its place as return-value documentation in the absence of an output 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?

For a two-parameter read tool with no output schema, the description covers what it returns at field level, how to address the record, and that it is read-only. It stops short of stating not-found behavior or which identifier takes precedence, which is the remaining hole for a lookup tool keyed on either a number or an id.

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?

With 0% schema description coverage, the description carries the load and mostly does: it explains that 'number' is passed as the human speaks it (example SO-1) and that 'order_id' comes from erp_order_list. Gaps remain — both parameters are optional and it never says whether one is required, whether both may be supplied, or which wins if they conflict.

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?

Opens with a specific verb and resource ("ONE sales order from the ERP with its lines") and the capitalized "ONE" immediately separates it from the list sibling erp_order_list, which it names. An agent can tell exactly what it retrieves and at what cardinality.

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 contrast with erp_order_list is embedded in the parameter guidance ("or the 'order_id' from erp_order_list"), which routes the agent to the list first when the id is unknown. Sample user utterances ("покажи замовлення SO-1", "склад замовлення") give concrete retrieval triggers, but there is no explicit when-not or statement of behavior when neither identifier is supplied.

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