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

Annotations already declare readOnly, idempotent, open-world behavior, so the bar is lower; the description still adds useful details about result ordering ('nearest first') and the fields returned (address, distance, capabilities, map link). The opening-hours caveat is a genuine behavioral note that annotations cannot convey.

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 the core action and scope, then the network coverage and result contents. Four sentences with essentially no filler; the opening-hours sentence is the only borderline item but it is actionable guidance.

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?

No output schema exists, and the description compensates by describing what comes back (nearest-first ordering, address, distance, available services, map link). Combined with the fully documented schema, an agent has everything needed to call this 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?

Schema coverage is 100% and every parameter already has a description, including enums for lang and network and the 1-5 bound on max_per_network. The description only restates the optional network filter, adding no syntax or format detail beyond the schema, so baseline 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?

States a specific verb and resource ('Find places near a Canadian postal code where a parcel can be dropped off or picked up') and enumerates the covered networks. This is clearly distinguishable from siblings like track_package or compare_shipping_rates without inspecting any schema.

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 context for use (locating drop-off/pick-up points near a postal code, no account needed) and explains the optional single-network narrowing. It does not name alternatives or state when not to use it, but the sibling set is far enough away that no confusion is likely.

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