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

No annotations are provided, so the description carries the full burden; it discloses that there is no market/symbol filter, that the response keys are market, market_time and trade_status, and that values are current status rather than a schedule. It omits auth/rate-limit behavior, but for a read-only status endpoint the scope and shape disclosure is substantial.

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?

Two tight sentences with the capability front-loaded and the disambiguating constraint immediately after. No filler, no restatement of the title.

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, so the description must convey the return shape, and it does by naming the returned fields and their codes. A zero-argument read tool whose response keys are enumerated needs nothing further.

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, so per the rubric the baseline is 4. The description reinforces this by stating 'No market or symbol filter', which prevents the agent from inventing filter arguments.

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?

States a specific verb (Get) and resource (CN/HK/US trading status plus RFC3339 market-local time) with scope explicitly defined as three markets. The contrast with get_trading_sessions ('this is current status, not the trading-session schedule') lets an agent disambiguate it from its closest sibling without opening either schema.

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 carves out a when-NOT-to-use case by stating this is current status rather than the trading-session schedule, which routes the agent away from get_trading_sessions. It does not name the alternative tool directly, but the condition that selects it is clear.

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