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

Annotations already declare readOnly, idempotent, non-destructive and non-open-world, so the safety profile is covered. The description adds genuine behavior beyond that: the 14-digit decode path, the occasional duplicate code after a village split, and the fields returned per village. It omits pagination/limit behavior, keeping it below 5.

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 and the ambiguity caveat before the parameter mechanics. Sentences are dense and every one carries information, though the mid-section runs long and could be split for faster scanning.

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 correctly shoulders the return-value burden by listing 8-digit code, names, type and bbox, and warns about duplicate codes. The only gap is pagination/limit semantics for a 7-parameter search that can return hundreds of matches.

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 baseline is 3, but the description goes further than the schema by explaining that kode is a prefix whose length (2/4/6/8 digits) selects province office, land office, kecamatan or village, and that nomor must be 14 digits. The nama+kecamatan/kabupaten/provinsi combination advice also clarifies how filters interact.

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?

Opens with a specific verb+resource ('Look up BPN villages') and immediately states the three lookup keys (name, code, certificate number). The mention of what is returned (code, names, type, bbox) confirms the resource is a village record, not a parcel, distinguishing it from Parcel_get/Parcel_search.

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?

Gives real operational guidance: names are substring-matched and ambiguous, so combine nama with kecamatan/kabupaten/provinsi, and use nomor to decode a certificate. It stops short of naming a sibling (e.g. Parcel_search) as the alternative for parcel-level queries, so routing is implied rather than explicit.

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