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

Annotations already declare readOnlyHint and openWorldHint, so safety is covered. The description adds substantive behavior beyond that: credit cost per record (minimum 2) and guidance to keep page_size small, plus null-vs-zero semantics for rating and review_count and the fact that min_rating>0 excludes unrated businesses. These are real operational traits not present in the annotations.

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?

Purpose is front-loaded and most sentences earn their place (cost, null semantics, category discovery). It loses a bit by re-quoting the lat/lon bounds that the schema already carries, adding length without new information.

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 an output schema and readOnly/openWorld annotations present, the description still supplies the operational context an agent needs: cost model, page_size discipline, category-value discovery path, and the alternate search tool. Pagination ceiling and full return shape are left to the schema, which is appropriate.

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. The description goes beyond the schema on `category` (exact, localized, non-ASCII, punctuation-bearing, discover via facet) and explains the unrated-exclusion behavior of `min_rating`. It redundantly restates the lat/lon ranges verbatim, which caps it below 5.

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 first sentence states a specific verb (searches), resource (stored Google Maps businesses), scope (near a coordinate), and the exact dataset ('google-map-businesses'). An agent can distinguish this proximity tool from datasets_google_map_search without inspecting either 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?

It names the sibling alternative (datasets_google_map_search) and tells the agent to use the category facet to discover exact filter values before filtering. It does not explicitly state the when-to-use condition versus the search sibling (e.g. 'use when you have coordinates'), so the routing cue is present but softer than a full when/when-not statement.

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