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

Adds substantial context beyond the readOnly/openWorld annotations: history starts at tracking_since, a free window of the last 30 days, and the important limitation that the reason for a drop is neither published nor inferred. It also enumerates what each change record contains, which shapes expectations of the result.

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 core question is front-loaded and the parentheticals carry real meaning rather than filler. It is dense with several clauses in one block, but every sentence conveys information an agent needs.

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?

An output schema exists, yet the description still usefully previews the change-record fields and the drop-reason limitation, and it covers historical boundaries (tracking_since, 30-day window). The only loose thread is the reference to 'history_window,' which is not among the listed siblings.

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 parameters are already fully documented, setting the baseline at 3. The description adds only the loose notion of 'since a date' and the free-window constraint, without clarifying filter interaction or limit semantics beyond the schema.

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?

States a specific verb and resource — changes (added/modified/dropped/reappeared) to registered support organizations on Japan's ISA list — with a clear temporal scope. It is immediately distinguishable from support_org_lookup, which would query the current list rather than the change history.

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?

Explains why this tool exists versus simply reading the current list: 'ISA publishes only the current list,' so historical changes require this service's own version records. That steers usage well but does not explicitly name the sibling tools or state exclusions.

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