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

Annotations already cover read-only, non-destructive, open-world, so the description's added value is the domain precondition (own carrier contracts) and the fact that returned data includes status and tracking events. Pagination/result-limit behavior for a list endpoint is not disclosed.

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 dense sentence plus the endpoint path, front-loading the resource and then the defining scope caveat. No filler or restatement of the title.

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?

With no output schema, the description usefully previews the return content (status and tracking events) and the eligibility constraint. The main missing piece for a list tool is whether results are paginated or bounded.

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?

The tool takes zero parameters, so there is nothing for the description to disambiguate; baseline for a no-param tool applies. The description adds no parameter-level confusion.

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?

Specific verb ('List') and resource ('trackers'), plus a precise scoping definition: shipments created outside shipcloud tracked via the carrier's tracking number. That scope cleanly separates it from shipcloud_list_shipments, though it does not name the get_tracker/create_tracker siblings.

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?

Gives a clear applicability rule — only trackers for shipments created outside shipcloud and only for your own carrier contracts — which tells an agent when this list is meaningful versus the shipment list. It stops short of explicitly naming alternatives or stating when not to call it.

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