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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so safety is covered. The description adds that results are a screening derived from cross-market signals and includes a not-investment-advice disclaimer, but says nothing about result ordering, freshness, or pagination behavior.

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 claim (what the tool returns and on what signal) is front-loaded, followed by timing, access, and disclaimer notes. The parenthetical ticker/peer examples are lengthy but illustrative; the sentence is dense but nothing is clearly 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-optional-parameter, read-only screening tool with no output schema, the description covers the signal logic, when to call it, and auth requirements. The main residual gap is what the returned records look like (fields, ordering), which is left implicit.

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 coverage is 100% and the single limit parameter is documented in-schema with its default and 1–23 range. The description never mentions limit or how many items are returned, so it adds no meaning beyond the schema; baseline 3 applies.

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 concretely states the output: Korean stocks whose overnight US leading indicators (VIX, Nasdaq 100 futures, SOX, Hynix ADR, US 10/30Y yields) moved sharply or whose FINRA short ratio jumped versus its 20-day average. That is far more specific than a restated title. It does not, however, explicitly contrast itself with siblings like market_indicators or market_insights.

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 gives clear situational context — call it before the Korean market opens — plus an access note (usable without a key). There are no explicit exclusions or named alternatives, so it stops short of full when/when-not guidance.

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