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

Annotations only say readOnly and openWorld; the description adds substantial context beyond that — per-layer refresh cadence (30 minutes for premium/funding/regime, daily for macro/regulation/calendar), units and ISO 8601 timestamps in every response, per-section sources with freshness, a $0.03 per-call price, and the x402 payment handshake including the fallback behavior when unpaid. For a paid tool this is exactly the behavioral disclosure an agent needs before invoking.

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 data inventory is front-loaded so an agent can decide within the first sentence whether the payload is relevant. It is a dense wall of comma-separated clauses rather than structured bullets, and the payment/HTTPS paragraph is long, but every clause carries information the caller 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?

There is no output schema and no parameters, so the description must carry the return-value burden — and it does, covering section contents, units, timestamp format, source attribution, freshness cadence, cost, and the unpaid-request fallback. An agent can invoke this correctly and predict the response shape without further information.

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?

The tool takes zero parameters and the description explicitly confirms 'No arguments,' matching the empty schema. With no parameters there is nothing further to disambiguate, so this sits at the baseline for a no-arg tool.

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 enumerates the concrete data it returns — Seoul/Tokyo session state, kimchi premium for 8 coins, BTC/ETH funding, BTC regime, Treasury yield/DXY/Asian FX, event calendars, US crypto regulation filings — so an agent knows exactly what resource this is. It never distinguishes itself from siblings like report_premium or brief_preview, which appear to overlap heavily, so it falls short of a 5.

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 statement of when to call this versus report_premium or brief_preview, both of which are plausibly overlapping report tools. The only usage-adjacent content is payment mechanics ('without payment the tool returns the payment requirements'), which tells the agent how to pay but not when this tool is the right choice.

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