get_water_zone_info

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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so the safety profile is covered. The description then adds genuinely new behavioral context: the exact return shape (including has_water_mesh, zone_extent, overlap_priority) and that it also counts linked bodies, which is the only source of output information since no output schema exists.

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 tight sentences: the purpose is front-loaded and the return contract follows with no filler. Every clause carries information.

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 single-parameter read tool with no output schema, the description is largely complete: it names the resource, the counting behavior, and the full return field set. The only gap is the absence of any usage/routing context, but nothing an agent needs to invoke it correctly is missing.

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 100% and the single parameter water_zone_label is fully documented in the schema as the label of the existing AWaterZone actor. The description adds nothing beyond that, so the 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?

Specific verb (read/count) plus a specific resource (AWaterZone) and its linked water bodies. The agent can distinguish this from get_water_body_info since that targets a different resource. It stops short of name-checking the closest siblings to route unambiguously.

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?

"an existing AWaterZone" implies a prerequisite (the zone must already exist), but there is no explicit when-to-use, when-not-to-use, or reference to an alternative such as get_water_body_info. The agent gets no guidance on tool selection.

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