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

Annotations only declare readOnlyHint=true and openWorldHint=false; the description goes further by specifying that events are returned in order and listing the allowed statusMilestone values. It does not discuss pagination or errors, but for a read-only lookup with an output schema this is adequate added behavioral context.

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 each earn their place: the return payload, the primary use case, and the statusMilestone enum. It is front-loaded with the core behavior and contains no filler.

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?

The tool is a simple read-only getter with one required parameter, a fully described input schema, and an output schema. The description covers what it returns, in what order, and when to use it, so an agent has enough to invoke 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?

Input schema description coverage is 100%, so the schema already documents trackerId and searchBy meanings. The description mentions needing a trackerId and alludes to status values, but adds no parameter-level detail beyond the schema, giving the baseline score.

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?

Description states a specific verb ('Returns') and resource ('full tracking results for an existing tracker') and enumerates the content: metadata, shipment status, events in order, and delivery statistics. It also marks itself as the primary tool for 'where is my package?' when a trackerId is available, distinguishing it from search-oriented 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?

The description explicitly says when to use this tool: when you have a trackerId and need package status context. It does not explicitly name sibling tools as alternatives or state when not to use it, but the 'primary tool for...' framing gives clear usage context.

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