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 fully covered by structured data. The description adds nothing beyond that—no note on what happens with an invalid/nonexistent id, no id format, no indication of response shape.

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?

One short sentence, front-loaded with the verb and resource, with no filler. It is lean to the point of under-specification, but nothing in it is wasted.

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 trivial single-record getter with annotations covering the safety profile and no output schema, minimal documentation is defensible. Still, the missing id-format guidance and lack of differentiation from the list/search siblings leave a real gap for an agent choosing between wilayah tools.

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 0% for the single required parameter, so the description bears the burden. 'By its id' only confirms the parameter's role and says nothing about the expected format (e.g., a BPS-style code like '32.73' vs a numeric row id) or validity constraints.

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 gives a specific verb and resource (get a single regency/city) plus the lookup key (id), which is clearer than the title alone. It does not distinguish it from close siblings like wilayah_list_kabupaten or wilayah_search, so an agent must infer that this is the single-record fetch.

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?

There is no guidance on when to use this versus wilayah_search (lookup by name) or wilayah_list_kabupaten (enumerate all). The only implicit signal is 'by its id', which requires the agent to already know id is unavailable via the other tools.

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