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

Annotations only declare the generic mutation profile (readOnlyHint=false, idempotentHint=true, destructiveHint=false, openWorldHint=true). The description adds the specific side effect (carrier and price are finalised, order transitions to Ready to Ship), the return payload (carrier, tracking, consignment, pre-signed PDF URLs valid 7 days), and a concrete failure semantic for 422. That is meaningful context beyond the structured fields.

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?

Front-loaded with a 'WRITE:' marker, then purpose, then behaviour, then error handling, then the endpoint. No sentence is redundant — each adds a distinct fact an agent needs.

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?

There is no output schema, so the description carries the return burden and does so (carrier, tracking, consignment, three document URLs with a 7-day validity). Mutation effects and the 422 recovery path round out everything needed to call it correctly.

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 a single parameter at 100% schema description coverage, the schema already explains that tracking_number comes from shippit_create_order and usually starts with PP. The description adds only the URL-path binding, so the baseline of 3 applies.

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 an explicit verb and resource ("confirm an order for shipping and fetch its label") and pins down the exact domain step. The closing endpoint reference (GET /orders/{tracking_number}/label) and the note that it precedes shippit_book_orders make it unambiguous against the eleven 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 clear sequencing guidance — this is the 'label' step, and labelling comes before shippit_book_orders — plus an explicit recovery path for the 422 case. It does not state when to avoid calling it (e.g. before a quote exists, or on an already-labelled order), so it falls short of full when/when-not coverage.

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