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

Annotations already cover the safety profile (readOnlyHint=true, destructiveHint=false, openWorldHint=false), so the bar is lower, and the description adds real behavioral value beyond them: it discloses the return shape (tracking events newest first) and the presence of a local_carrier_tracking_url with its meaning. It stops short of noting failure modes such as an unknown or not-yet-shipped tracking number.

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?

Three short sentences, front-loaded with the action and lookup key, then the return content, then the guidance. Every sentence adds information with no repetition of the title or schema.

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 correctly assumes the burden of describing returns and does so (events newest first, carrier link). It is nearly complete for a single-parameter read tool, with only error/empty-result behavior left unspecified.

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?

Only one parameter exists and schema description coverage is 100%, including an example format (SAM12345678), so the schema carries the semantics. The description confirms the lookup is by tracking number but adds no format, validation, or edge-case detail beyond what the schema already provides.

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 (track) and resource (SAMOS parcel) plus the lookup key (tracking number). No sibling tool does tracking, so it is unambiguously distinguishable from estimate_duties, estimate_shipping_price, list_destinations, and search_help.

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 gives an explicit usage instruction for the returned link ('Share that link when the user wants more delivery detail'), which is genuinely helpful routing guidance for output consumption. However, it says nothing about when to select this tool versus the pricing/destination siblings, and there are no exclusions or prerequisites stated.

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