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

Annotations already declare readOnlyHint=true, so the safety profile is covered. The description adds the payload shape (lines, totals, customer, warehouse) and the underlying endpoint, but says nothing about auth scope, rate limits, or whether missing Guids error vs. return empty.

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?

Two tight sentences with the essential lookup key front-loaded and the endpoint reference trailing. No filler; every clause carries information.

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 single-resource read with no output schema, the description usefully enumerates the returned content and the read-only annotation covers safety. Only the error/empty-result behavior is left unaddressed, which is a minor gap.

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 both orderGuid (with pattern) and serialBatch are already documented in the schema. The description only restates the Guid lookup and the returned fields, adding no syntax the schema lacks. 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?

States a specific verb (Fetch) and resource (a single sales order) and pins the lookup key (by Guid), plus enumerates what comes back (lines, totals, customer, warehouse). The word 'single' contrasts with the plural list_sales_orders sibling, though it never names that sibling explicitly.

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?

Usage is implied: fetch one order when you already have its Guid. There is no explicit when-to-use/when-not guidance, no mention of when to prefer list_sales_orders (e.g., when the Guid is unknown), and no stated prerequisites.

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