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

Annotations (readOnly=false, idempotent=false, openWorld=true) signal a non-free, non-cacheable external fetch, and the description adds real value on top: it is paid from the account balance, priced like google_search, and exposes only rating/review count rather than full review text. It does not restate annotation claims, and the pending_ids/wait_seconds behavior is covered by the schema.

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?

Four front-loaded sentences: what it collects, what each listing contains, who it is for, and cost/return caveats. Nearly every clause earns its place, though the field enumeration overlaps slightly with the return-value caveat.

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 enumerates the returned fields (rank, name, CID, category, address, website, rating, review count, opening status, snippet) and delimits reviews to counts only. Cost model and ordering are stated; only cross-sibling disambiguation for web-vs-maps intent remains thin for a 9-param tool.

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 100% across all 9 parameters, so depth, domain, geolocation, priority, language/location pairing, and max_items_per_block are already fully documented. The description adds no parameter-level syntax or constraint beyond what the schema provides, which is the baseline-3 case.

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 (collects), resource (Google Maps listings), ordering guarantee, and per-listing fields. The use-case clause ('local SEO, local competition, market research') implies it is the local/maps counterpart to google_search, but it never explicitly contrasts the two, so sibling differentiation is left partly to inference.

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 use-case list ('local SEO, local competition and market research') and references google_search only for pricing parity, not as an alternative to route away from. There is no 'when not to use' and no named alternative for web SERP intent, even though google_search and ai_overview_sources are obvious siblings.

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