search_online

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

Annotations already declare readOnlyHint and openWorldHint, so the safety/live-network profile is partially covered. The description adds non-obvious behavior: the query is dispatched to a single site only, and it enumerates the returned fields, which goes beyond the structured data. It does not discuss rate limits or failure behavior, so it falls short of 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 tight sentences, front-loaded with the action and scope, then the routing rule. Listing the returned fields overlaps with the existing output schema, which is the only mild redundancy.

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 present, leaving return values to the schema is acceptable, and the description covers the routing decision well. However, for a tool with five optional filters that are undocumented in both schema and description, the definition is still not fully complete for an agent trying to construct a query.

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 only 29% across seven parameters, so the description must compensate for given, surname, place, year_from and year_to, and it largely does not. The 'name_variants' sentence hints that name fields are run repeatedly, but no parameter's format, default, or interaction is clarified.

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 ('Search an open database live'), names the return payload, and explicitly distinguishes itself from the sibling search_links for sites lacking an open API. An agent can pick between search_online and search_links without opening 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?

Gives a concrete usage rule ('Run it for each name form from name_variants') and names the alternative plus the condition that selects it ('sites without an open API use search_links'). The one-site-per-call constraint is also stated, preventing misuse.

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