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

No annotations are provided, so the description carries the full disclosure burden. It usefully states the required inputs and the ask-don't-guess rule for a missing postcode, but says nothing about permissions, what happens when no POD exists, or error/empty-result behavior in a courier lookup.

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 purpose, then usage triggers, then input requirements and the missing-postcode rule. Every sentence carries information; only the parenthetical 'proof of delivery / POD' is mildly redundant.

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 compensates by naming the returned fields (location, signature source). All three required params are covered and the missing-input workflow is handled, leaving only failure/empty-result handling unstated.

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 already documented, including examples for system, postcode, and trackingNo. The description restates the required set and clarifies postcode means 'the collection or delivery postcode for that parcel', a marginal addition over the schema.

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+resource ('Get proof-of-delivery details for a parcel') and enumerates what is returned (delivery/collection location and recipient signature). It is clearly separable from get_parcel_tracking, though it never names that sibling to sharpen the contrast.

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 concrete trigger conditions ('where a parcel was delivered', 'who signed for it', 'POD') and a fallback behavior when the postcode is unknown ('ask the user rather than guessing'). It does not name alternatives such as get_parcel_tracking for status-only queries, so routing guidance is clear but not exhaustive.

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