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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is fully covered. The description adds useful context that filters are 'vertical-specific verified booleans' and lists which ones exist for hotels, but says nothing about result volume, pagination, or what a record contains.

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?

Dense but front-loaded: purpose first, then valid verticals, then parameters, then an example. The enumerated filter keys are long but earn their place given the schema gap; no filler sentences.

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 7 parameters, a nested open-ended filters object and no output schema, the description covers purpose, verticals and filter keys but omits the lang parameter, the limit default/range, and any sense of result shape or paging. Adequate to make a correct call, not complete for the tool's actual complexity.

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 low at 29% (only lang is documented inline, and filters only says 'see list_verticals'), and the description fills much of that gap: it names vertical as required, enumerates country, area, query, filters and limit, spells out hotel filter keys (spa, pool, parking, pets, ski_in_out, family, min_stars, type), and gives a usage example. The main miss is that 'lang' goes unmentioned in the description.

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 across entityindex.ai verticals') and explicitly positions itself against the vertical-specific siblings by saying it serves 'same data as the vertical-specific tools.' An agent can tell it is the generic entry point versus search_hotels/search_restaurants, though it never states outright which to prefer.

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 the roster of verticals ('hotels' and 'restaurants', country 'andorra') and routes to list_verticals for discovery, plus a concrete worked example. It never says when to pick this over search_hotels or search_restaurants, so the choice between generic and specific is left to inference.

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