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

With no annotations, the description carries the behavioral burden and does so well. It discloses the approximate 15-minute delay, the free yfinance source, that it does not consume the live-fetch quota, and that valuation metrics are 'best-effort.' These caveats materially shape an agent's expectations and are beyond what structured data could convey.

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 summary line front-loads the tool's purpose, the returns list is compact and information-dense, and the caveats about delay, quota, and pairing are each worth their sentence. No filler is present.

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 a single obvious parameter, an output schema that documents return values, and a clear set of sibling tools, the description is complete. It covers data freshness, cost/quota behavior, reliability caveats, and suggests complementary tools, so an agent has everything needed to invoke it correctly.

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?

There is only one parameter, 'ticker,' and the schema provides no description (0% coverage). The description says the tool is 'for a ticker' and mentions yfinance, which lightly hints at the ticker format, but it does not explicitly specify the expected symbol format or normalization rules. It adds marginal value over the parameter name.

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 opens with a specific verb-plus-resource statement: 'Live price + volume + turnover (换手率) + market cap + basic valuation for a ticker.' It then enumerates the exact returned fields, making it clear this is a quote/basic market data tool and distinct from the analytical/sentiment siblings like score_ticker and fundamentals.

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 gives clear context on when to use it: for a quick, free quote that does not consume the daily live-fetch quota, and it advises pairing with score_ticker / fundamentals / analyst_track_record for a fuller picture. It stops short of explicitly stating when not to use this tool versus alternatives, but the positioning is clear.

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