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

Annotations already mark this read-only and idempotent, and the description adds crucial non-obvious behavior: the network is small and mostly sample data, demo entries are named [DEMO] and flagged is_demo, so the agent must check that field before acting. This goes beyond the safety profile in the annotations.

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 description is longer than average but well organized: what it does, critical demo-data warning, examples, usage boundaries, and cost/latency all earn their place. The minor example error and slightly repetitive availability-window mention in the schema keep it from being perfect.

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 6-parameter nested-object tool with no output schema, the description plus schema covers invocation, the most critical data-quality caveat, and the alternative for real availability. It does not explain ranking criteria or the shape of results beyond is_demo, but enough is present for an agent to select and call the tool correctly.

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?

Three worked examples map natural-language requests to vertical, location, and capability values, which helps a lot. However, price_band, max_results, and radius_miles receive no real explanation beyond their names/defaults, and the 'dentists in London' example incorrectly uses capability 'plumbing'. Schema coverage is only 50%, so the description does not fully compensate.

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 states a concrete operation ('return ranked candidate businesses') on a specific resource (our supply network) and lists the filtering criteria. It also distinguishes this lookup from directory browsing and from situations where a specific SMB is already known, which separates it from sibling verification/calling tools.

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 explicitly says to call this before schedule_appointment or send_message when no specific SMB target exists, and gives a WHEN NOT TO USE block covering general browsing and already-verified identifiers. That is concrete routing guidance, not just an implied use case.

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