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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so safety is covered. The description adds useful behavior beyond that: what each result contains (descriptions, business kind, reporting mode, website links) and the explicit negative scope around private founder data and financial proof.

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?

The core instruction is front-loaded and sentences are purposeful. There is mild redundancy — 'An empty query browses the directory' essentially repeats the earlier 'use an empty query to browse examples', and the return-content sentence overlaps the schema's kind field.

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 correctly takes on the burden of explaining return values and scope limits, and it does so adequately. The remaining gap is pagination behavior for limit/offset, which an agent browsing a directory would likely need.

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 50%, and the description carries the query parameter well, adding 'use short keywords' and 'do not send the whole question' beyond the schema text. However, limit and offset are documented in neither the schema description nor the description, so pagination semantics remain unexplained.

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?

The description names a specific verb and resource — searching the published Auto Units business directory by company name, offering, or subject — so the agent knows exactly what the tool retrieves. It does not explicitly distinguish itself from the sibling prepare_business_brief, which is the only missing piece for a 5.

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?

It gives concrete usage rules: use an empty query for general requests like 'I want to start a business with AI', use short subject keywords for specific interests, and do not send the whole question as the query. It states exclusions (no private founder businesses, financial results, or proof of commercial success) but never routes the agent to the sibling prepare_business_brief.

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