list_zones

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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety is covered. The description adds genuinely new behavior in "best first" (sort order) and "candidate" (pre-filtered result set), but says nothing about result limits, pagination, or what happens with a null region. Useful but thin given the low bar.

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?

A single sentence, zero filler, with the filter condition and sort order front-loaded. Every clause carries information the agent needs.

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 an output schema present and annotations covering the read-only profile, the description does not need to explain return values. The remaining gap is the unaddressed relationship to rank_zones and the absence of any result-size behavior, which leaves the agent guessing at boundaries.

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% and both parameters carry their own descriptions ("Region filter", "Minimum score, 0-1"), so the schema does the heavy lifting. The description reinforces that min_score is inclusive ("at or above") but adds no format detail for region, so baseline 3 applies.

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 pairs a specific verb ("List") with a specific resource ("candidate drill zones") plus the qualifying condition ("at or above a score") and output ordering. It is distinct from get_zone by being plural/listing, but it never acknowledges rank_zones, which sounds closely related, so sibling differentiation is incomplete.

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?

The phrase "at or above a score" implies the usage context (threshold-based candidate selection), which is more than nothing. However, there is no explicit when-to-use/when-not guidance and no routing to rank_zones or get_zone for agents weighing alternatives.

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