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

No annotations are supplied, so the description carries the full behavioral burden. It usefully discloses the cost model ($0.01 per call, x402/USDC), but says nothing about result volume, pagination, failure behavior, or whether repeated calls with the same t are idempotent — all relevant for a paid polling endpoint.

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 short sentences with no filler: the resource and temporal scope lead, and the pricing note trails compactly. Slightly more could be gained by folding the pricing into a parenthetical, but nothing 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 single-parameter tool with full schema coverage the description covers the essentials of when it returns data. Since there is no output schema, the absence of any hint about the shape of returned update records (fields, identifiers, ordering guarantees beyond the schema's note) leaves a real gap.

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 't' parameter's format, future-date restriction, exclusive comparison and ordering are already fully documented in the schema. The description's phrase 'first observed after timestamp t' adds only a minor nuance over the schema's observed_at > t.

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?

Names a specific resource (Japanese authority updates from FSA, BOJ, MOF) and a specific scope (first observed after timestamp t), which is more precise than a tautology. It does not explicitly distinguish itself from siblings like jp_authorities_latest or jp_authorities_search; the 'since' semantics are implied rather than contrasted with alternatives.

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?

The description implies incremental/delta polling ('first observed after timestamp t'), which gives an agent a workable sense of when to use it. However, it never states when NOT to use it or names jp_authorities_latest / jp_authorities_search as the alternative for a snapshot or keyword-based lookup.

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