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

Annotations declare readOnlyHint=true and idempotentHint=true, so the tool is safe to call repeatedly. The description adds that data is 'delay' for futures and oil due to free pricing, which is important behavioral context not in annotations. It also mentions timestamps are included, providing clarity on return format.

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 description is a single, dense paragraph that front-loads the list of indicators and includes key caveats (delayed data, no key needed). It is reasonably concise for the amount of information, but the English parenthesis feels a bit redundant and could be trimmed.

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?

Given the tool has no parameters, no output schema, and focuses on a simple list of indicators, the description covers the essentials: what indicators, that timestamps are included, and the data-delay caveat. It could mention the absence of pagination or any filtering, but that is not critical when there are no inputs.

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 has zero parameters, so the description need not explain parameter usage. It does a good job of explaining the output scope (which indicators) and the fact that no key is needed, which compensates for the lack of parameter structure.

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 clearly states what the tool does: it lists specific market indicators (KOSPI200 futures, FX, oil, US leading indicators) and notes that timestamps are included. It distinguishes itself from siblings like market_map and market_rankings by focusing on raw indicator values rather than visualization or rankings.

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 usage: it is for retrieving market data with no parameters, usable without a key. It does not explicitly state when not to use it compared to alternatives, but the context of siblings (market_map, market_rankings) suggests different purposes, and the lack of parameters makes it a simple fetch-all tool.

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