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

No annotations are present, so the description carries the full burden. It discloses the read-only nature ('只读查询') and the scope constraint (only valuation metrics, not price data). While it doesn't mention rate limits or auth, these are not critical for a simple read query, and the read-only trait is explicitly stated. This goes beyond a bare 'get' and adds a meaningful behavioral constraint.

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?

Three sentences, each earning its place: the first defines the deliverable, the second gives usage and alternative routing, the third adds read-only and format. No filler, and the key discriminator (vs ashare_sector) is front-loaded. Efficient and perfectly scoped.

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 single-parameter read-only tool with an output schema already present, the description covers all that an agent needs: purpose, when to use, when not to use (with named alternative), read-only status, and code format. Nothing is missing for correct invocation.

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 schema covers the parameter with an example, but the description adds the format rule 'pt 前缀 + 8 位' (pt prefix + 8 digits), which is structural guidance beyond the schema's simple example. This gives the agent a template to validate the input, exceeding the baseline of 3.

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 the exact deliverable — valuation metrics (PE/PB/PS/PCF, dividend yield, historical percentile) — and explicitly contrasts with the sibling ashare_sector, which handles price change and leading stocks. The verb '估值' (valuation) plus the resource '板块' makes the purpose unambiguous and distinct from all 21 siblings.

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?

It states precisely when to use this tool ('用户问某板块贵不贵/估值分位') and explicitly warns to use ashare_sector instead when looking at price change or leading stocks. The alternative tool is named, and the condition for choosing it is given — no inference is required.

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