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

Annotations already declare readOnlyHint=true, idempotentHint=true, openWorldHint=true, destructiveHint=false, so the safety profile is covered. The description adds analytical interpretation (what rising balances mean) that annotations cannot convey, but says nothing about data freshness, update cadence, or whether balances reflect end-of-day vs intraday. With annotations carrying the mutation profile, the added analytical context is useful but not rich behavioral disclosure.

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, front-loaded with the resource and scope, then interpretation, then example queries. Efficient and structured. Slightly verbose in the interpretation clause, but every sentence carries information.

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?

Complete for a read-only single-parameter data tool: the description explains what is returned (financing, short-sale, buys/sells/covering, quota) and how to interpret it, and annotations cover the safety profile. No output schema is present, so the description's enumeration of returned fields is a genuine value-add, though it doesn't mention units or data latency.

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?

Schema description coverage is 100% and the single parameter is fully documented in the schema (comma-separated, resolves codes/abbreviations/Chinese names, up to 20). The description adds nothing beyond restating the domain of the symbol. Baseline 3 is correct when the schema does the heavy lifting.

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+resource: 'Margin financing (融資) and short-sale (融券) balances for a Taiwan-listed stock.' It further disambiguates scope by listing the included fields (day's buys, sells, covering, exchange quota), distinguishing it from siblings like taiwan_stock_quote or taiwan_foreign_holdings.

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?

Provides interpretive context ('rising margin balance means leveraged retail buying', 'classic squeeze setup') and example queries, which implies usage. However, it never states when to use this tool versus any sibling, nor any exclusions (e.g., non-Taiwan listings). Guidance is implied, not explicit.

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