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

The description goes well beyond the readOnly/destructive annotations by disclosing the two-state behavior (returns nothing when there is no overlap), the advisory nature of mining-terrain intersections rather than legal determinations, and the fact that groundwater extent alone imposes no restriction. It also discloses the 4-token cost and refund condition, which is not visible anywhere else.

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 long, but the length is earned: there is no output schema, so the return structure and critical legal/cost caveats must be spelled out. It is front-loaded with the main function, then layers detail and caveats in a logical order, though some phrases could be tightened.

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?

Without an output schema, the description fully compensates by enumerating the per-plot fields, statuses, mineral classes, per-object lists, and the empty-result behavior. It also covers the advisory nature, the non-restriction of groundwater extents, and the alternative tool, leaving an agent with everything needed to call and interpret 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?

Schema coverage is 100%, with transaction_id already documented as a UUID from search results. The description confirms the parameter is a specific transaction ID but does not add new parameter-level meaning beyond the schema, so the baseline of 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 opens with a specific verb and resource: 'Get the parcel-by-parcel subsurface breakdown for one transaction across two dimensions: mining terrains and major groundwater reservoirs.' It clearly differentiates itself from siblings by naming get_parcel_report as a shallower alternative and by scoping to a single transaction.

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 'Use it for a specific transaction to see whether its land overlaps a mining terrain or a major groundwater reservoir, and the per-object detail,' and it contrasts with get_parcel_report's one-line summary. This gives the agent a concrete selection rule among many transaction-sibling tools.

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