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

Annotations already establish read-only, idempotent, closed-world behavior, and the description adds real value on top: a hard cap of 10 results, the ranking precedence (exact city, then state/province, then country), loose spelling matching, and the exact fields returned. It stops short of saying what happens when nothing matches or how to interpret a zero-result response.

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?

Front-loaded with purpose, then result shape, then input formats, then trigger — a logical order with no filler. The return-field enumeration is dense but each item earns its place by preempting a follow-up call.

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 carries the return contract and does so thoroughly (fields, ordering, cap). The only material gap is edge-case behavior: empty results, and whether the agent should fall back to request_custom_list.

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 100%, so the baseline is 3; the description goes slightly beyond by spelling out accepted location granularities (city, state/province, country) and disclosing that spelling is matched loosely — a behavior not captured in the schema. Trade semantics are largely duplicated from the schema's list_trades reference.

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 ready-made business contact lists') plus the dimensions searched (industry, location). It is clearly distinguishable from siblings such as get_list_details (per-list lookup) and request_custom_list (bespoke lists).

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?

Ends with a concrete triggering scenario ('when someone needs leads or prospects of a type of local business'), which gives an agent a clear use condition. However, it never names the alternatives — notably request_custom_list when no ready-made list matches — so the routing is left implicit.

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