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

Annotations only say readOnly/openWorld/non-destructive, but the description discloses cost (4 API tokens), the refund policy (unknown, not_computed), timeout behavior, and the meaning of each state including the explicit warning that 'unknown' is never a claim that no plan exists. It also adds scoping caveats (extent is not a buildability statement, not legal advice) that annotations cannot convey.

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?

It is front-loaded: what it returns, then when to use it, then what it is not, then the state vocabulary and cost. It is dense but each block carries decision-relevant information; the state enumeration is long but necessary since those values drive follow-up behavior.

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 compensates by listing the returned fields per plan (title, resolution, legal status, share, links, check date) and by fully defining the state vocabulary and its billing consequences. An agent has everything needed to decide, call, and interpret the result, including what to do on unknown or not_computed.

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 the single parcelId parameter is already documented in the schema with both cadastral-id formats and UUID. The description only implies the input is a parcel and adds no format or validation detail beyond the schema, 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?

The first clause names a specific verb and resource ('local spatial development plans (MPZP) that cover one land parcel') and enumerates exactly what is returned per plan. It then explicitly disambiguates from siblings: not the general plan (POG), not get_transaction_layer(layer="planning"), and not the full get_parcel_report.

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 gives a literal selection rule ('Use it for "which local plan covers this parcel"') and redirects everything else to get_parcel_report, noting that report call already includes this section. It also names the fallback path for unknown state (get_parcel_report(preset="zoning")) so the agent knows the next call.

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