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

Annotations cover the safety profile (readOnlyHint=true, openWorldHint=false), and the description adds genuinely non-obvious behavior: the index is restricted to no-KYC services, and each hit carries KYC level, Privacy/Safety grades, and incident count. It omits ranking/ordering behavior for matches, which keeps it 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?

Two sentences, zero filler, with the search scope front-loaded and return shape second. Nothing repeats the title verbatim.

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 summarizes returned fields, and the three-parameter surface is simple. Missing only ordering/relevance behavior and how the limit interacts with total results.

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 67%: query and category are already documented in the schema, and the description largely restates them. The description does clarify that category scoping is optional ('optionally within one category'), but says nothing about the undocumented limit parameter beyond what its default/max implies.

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 ('Find no-KYC services') plus the matching fields (name, website domain, description) and an optional category scope. It is clearly a search-style lookup, distinct from siblings like get_service or rank_category, though it never names an alternative explicitly.

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?

Usage is implied by the matching-field enumeration: use it when you have a name, domain, or keyword. There is no explicit when-not guidance and no routing to siblings such as get_service (single lookup) or compare_services, leaving the agent to infer the boundary.

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