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

Annotations already declare read-only, idempotent, non-destructive, closed-world behavior. The description adds real behavioral context beyond them: results are ordered nearest-first and include distance and direction, and radius is bounded 10–200 m. It omits result-count limits or empty-result behavior, so not a 5.

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 ordering, then use case, then input modes and bounds. Every sentence carries information; 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?

No output schema exists, and the description covers the key return characteristics (ordering, distance, direction), which is the essential missing piece. It stops short of noting result-count caps or no-match behavior, leaving a small gap.

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%, so baseline is 3, but the description adds non-obvious semantics: the caller supplies *either* code *or* lat+lng, which the flat all-optional schema does not express. Radius range is merely repeated from 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 (List) plus resource (WIA Pin Code cells) and adds scope/ordering ('around a point or a code, nearest first, with distance and direction'). This is clearly distinct from siblings like pin_code_decode/encode or generate_wia_code, which do different things.

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 a concrete use case ('which codes cover this building/plaza') and states the two accepted input modes plus the radius range, so the agent knows when and how to call it. It does not name alternatives or state when-not to use it, so it falls short of 5.

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