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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, so the safety profile is covered. The description still adds real behavioral value: results are ordered nearest-first, distances are returned in meters, and the 5 km cap is stated up front.

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, front-loaded lines: what it does, when to use it, then a runnable example. No filler, and the example shows both the coordinate and the address form side by side.

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 usefully discloses the return shape (distances in meters, nearest first). For a 7-parameter tool, the remaining gap is the undocumented limit and lang behavior, and the absence of any hint on how this differs from places_search.

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 only 29%, so the description has to compensate. It does explain the lat/lon vs. address ('where') alternative and shows radius_m in use, but says nothing about limit (default 10, max 40) or lang, leaving two parameters essentially undocumented.

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 ('finds places of one kind') plus the scoping constraint (around a point or address, up to 5 km, nearest first). It clearly conveys what the tool returns, but it never contrasts itself with the sibling places_search, which is the most likely confusion point.

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 explicit 'Use when:' clause with concrete examples (closest pharmacy, ATM, charging station) gives a clear situational trigger. It stops short of naming when NOT to use it or pointing to places_search/geocode_address as alternatives when this tool is the wrong fit.

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