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

Annotations already declare readOnlyHint, destructiveHint=false, and openWorldHint, so the safety profile is covered. The description adds that results include 'full order details' and exposes the endpoint, but says nothing about pagination, result caps, or authentication needs. Some value added, but modest beyond 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?

Two compact sentences, front-loaded with the filter and result scope. The trailing 'GET /api/orders/delivered' is low-value implementation detail an agent can't act on, a small redundancy.

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-parameter read tool with full annotation coverage, the description covers what it returns ('full order details') and what it filters on. However, it omits pagination or result-limit behavior and whether partial matches are returned, which matter for a list tool.

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 coverage is 100%, so baseline is 3, but the description genuinely clarifies an ambiguous parameter: it specifies that order_ref means the *customer* reference, not an internal order id. That disambiguation adds meaning beyond the schema's terse 'The order reference to look for.'

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 ('List'), resource ('delivered orders'), and filter ('carry a given order reference'), plus the return scope ('full order details'). The 'delivered' qualifier naturally distinguishes it from siblings like list_orders and list_shipped_orders, though it never names an alternative 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?

The description implies you call it to find delivered orders for a reference, but gives no explicit when-to-use guidance and never contrasts it with close siblings such as search_orders, list_orders, or get_order. The agent has to infer the selection condition.

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