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

No annotations provided, so description carries burden. It discloses data currency (current period) and distinguishes from T-1. But it does not explain output structure or any limitations beyond data currency, which is partially mitigated by output schema existing.

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?

Concise, front-loaded with key purpose, includes warning and free tool note. Slightly dense with many details but useful; no fluff.

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 tool with output schema, description covers usage context, data categories, and sibling distinction. Complete enough for correct invocation, though return format is left to output schema.

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?

Zero parameters, so schema is trivial. Description adds context on data scope and usage, but does not describe any parameters since none exist. High value in explaining what the output covers.

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?

Description states it provides market breadth data with enumerated contents (up/down counts, limit-up/down, distribution, turnover). Purpose clear, but does not explicitly name siblings to differentiate beyond mentioning ashare_market_overview.

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?

Explicitly tells when to use ('user asks today's up/down counts...') and when not to use (warning against ashare_market_overview for same data due to T-1 discrepancy). Also notes it's free/no key.

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