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

Annotations already declare read-only and idempotent behavior. The description adds useful behavioral context: it requires no key, reflects a public-screen top market-cap range, and explicitly states it is not investment advice. No contradiction with annotations.

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 short, front-loaded with the core behavior, and each sentence adds useful content. The English parenthetical repeats some Korean content, creating minor redundancy, but the overall structure is efficient.

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 zero-parameter, read-only market overview with no output schema, the description sufficiently explains what the tool shows, the coverage scope, the access requirement, and the advisory disclaimer. Nothing necessary for correct invocation is missing.

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?

This tool has zero parameters, and the input schema fully reflects that. The description adds the relevant access note that no key is needed, which is useful, but there is no parameter meaning to elaborate on.

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 the tool's action and resource: viewing a sector-based market map with market-cap-weighted moves and representative stocks. It implies differentiation from sibling tools like market_indicators and market_rankings by describing a specific 'market map' view, though it does not explicitly name 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 provides no explicit when-to-use guidance or comparison to alternatives such as market_indicators, market_rankings, or overview. It mentions that the tool needs no key and matches the public screen, which is useful context, but it does not clarify when an agent should select this tool over others.

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