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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint, so the description carries a lower burden. It adds value by disclosing the data sources (Sina + Eastmoney, keyless) and the sentiment gauge (limit-up count). 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 a single, well-structured sentence beginning with the core purpose, followed by details and example queries. No wasted words; every sentence adds value.

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 no output schema and no parameters, the description covers the key output fields (index levels, change %, range, turnover, limit-up count). It could specify the exact structure or field names, but overall it's sufficiently complete for a simple snapshot tool.

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?

No parameters exist (schema coverage 100%). With zero parameters, the baseline is 4. The description explains what the output contains, compensating for the lack of explicit parameter docs.

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 uses a specific verb ('snapshot') and clearly states it provides headline index levels, change %, day range, turnover, and limit-up count. It distinguishes from siblings like ashares_quote (individual quotes) and ashares_limit_up (details on limit-up) by being a broad 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?

The description includes example queries ('how is the China A-share market doing', 'Shanghai Composite today'), making it clear when to use. It does not explicitly mention when not to use or name alternatives, but the sibling context implies this is for aggregate snapshots. Slight room for improvement.

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