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

Goes well beyond the annotations: it discloses credit-charging conditions, the Apify-vs-OpenStreetMap fallback chain, the dataSource discriminator on each row, and the caveat that empty results or missing ratings are not measured coverage. This is exactly the behavioral context the readOnly/openWorld hints 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 purpose, then routing, then cost/fallback semantics. Dense but each sentence carries distinct information; the all-caps emphasis is heavy but the content is not padded. Slightly long, keeping it just short of 5.

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?

For a 5-param, nested-schema tool with no output schema, the description covers sourcing, cost, fallback behavior, and result interpretation. An agent has everything needed to call it and to report its output honestly.

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 the baseline is 3, but the description adds real semantic value: categories are 'common category names' matched best-effort on OSM, and an empty category result may mean unmapped rather than absent. It meaningfully enriches how categories results should be read, though it does not touch query/limit/near beyond what the schema says.

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+resource ('Searches local business listings near a coordinate') and explicitly scopes out siblings: 'it does not run Maps rank checks or Q&A', naming the boundary with get_local_pack_rank and get_google_business_questions. An agent can distinguish it from other search tools without opening a 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 explicit when-to-use ('find local business candidates or nearby competitors') and when-not ('does not run Maps rank checks or Q&A'), plus how the result should be interpreted (never present OSM as the complete set). Routing guidance is fully specified.

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