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

Annotations already declare readOnlyHint, openWorldHint and non-destructive behavior. The description adds useful behavioral context beyond that: it names the external carrier network being searched and indicates the result includes opening hours and distance. It does not discuss pagination, rate limits, or error behavior, but against the annotation coverage this is solid.

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 core action and followed by the required input modes and endpoint. There is no filler or repetition.

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?

For a read-only search with ten parameters and no output schema, the description covers the main purpose and two return fields, but it leaves out the required carrier list and the meaning/behavior of limit, radius, and state. It is minimally adequate but not complete enough to prevent misuse.

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 only 40%, so the description needs to compensate, and it partially does by grouping address fields (street, zip_code, city, country) versus latitude + longitude. However, it omits the required `carriers` parameter entirely, along with `state`, `limit`, and `radius`, leaving important invocation semantics unaddressed.

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?

The description states a specific verb (Search) and resource (a carrier's parcel shops, lockers and drop-off points), plus scope (near an address or coordinates). No sibling tool covers drop-off/pickup location lookup, so this is clearly distinguishable.

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?

It implies when to use the tool by saying to provide an address or coordinates, but it never explicitly contrasts with alternatives or states when not to use it. The usage context is inferred from the tool name and the input-mode sentence rather than stated as guidance.

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