compare_articleCompare two versions of the same article in a Japanese law and show changed lines, with - for old and + for new. Dates must be 2017-04-01 or later.
同じ条の二つの時点の条文を比べ、変わった行を示します（- が旧、+ が新）。どちらの時点も 2017-04-01 以降。
| Name | Required | Description | Default |
|---|---|---|---|
| to | No | 新の時点 YYYY-MM-DD。省略で現行 | |
| law | Yes | 法令名・略称・法令ID | |
| from | Yes | 旧の時点 YYYY-MM-DD | |
| article | Yes | 条番号。例: 8、第八条、36条の2 |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full disclosure burden. It usefully explains the diff output notation and the date lower bound, but does not state permissions, error behavior, or what happens when no lines change.
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 compact sentences, front-loaded with the comparison purpose, then the output notation and date constraint. Every clause adds useful information without repetition.
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 read-only diff tool with full schema coverage but no output schema, the description adequately explains the return shape and the date lower bound. It leaves minor behavioral details unstated, such as error handling and when to prefer siblings, but is otherwise complete.
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%, so the baseline is 3. The description adds a meaningful constraint beyond the schema patterns: both 'from' and 'to' time points must be on or after 2017-04-01, and it frames 'from'/'to' as old/new comparison points.
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 states a specific verb and resource: compare the same article at two points in time and show changed lines with '-' for old and '+' for new. This distinguishes it from siblings like get_article and law_history without requiring the schema.
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 clearly sets the usage context: same article, two time points, both on or after 2017-04-01. It does not explicitly name alternatives or exclusions, but the comparison purpose is unambiguous.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.