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 genuinely useful behavior beyond that – the 'active' filter and 'soonest first' ordering – but says nothing about truncation when more than `limit` shipments qualify or how ties/undated shipments are handled.

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 sentence, zero filler, with the scope filter front-loaded before the default and ordering details. Nothing could be removed without losing 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 simple read-only list tool with three optional, fully documented parameters and rich annotations, this covers what an agent needs to select and call it. The only omission is the result-count/truncation behavior when the 50-row default caps the list.

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 all three parameters are fully documented in the schema itself. The description only echoes the default window of 7 days and adds no new meaning about `days`, `limit`, or `company` beyond what the schema provides – baseline 3.

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 gives a specific verb (implicitly 'list') plus a precise resource and scope: 'Active shipments whose ETA falls within the next N days (default 7), soonest first.' This is clearly distinguishable from delayed_shipments and list_shipments via the 'active' + ETA-window framing, though it never names those siblings 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 only implied by the scope statement – an agent can infer this is for upcoming-delivery views, but there is no explicit 'use this when' or 'use delayed_shipments instead for X' guidance. No prerequisites or exclusions are stated.

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