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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It states the data categories returned but does not disclose whether this is a read-only operation, whether it requires any special permissions, what the output format is, or whether the data is historical/current. For a data-retrieval tool this is a moderate gap, but the description does at least clarify the scope of the data.

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 concise sentence that front-loads the resource and then lists the data dimensions. It is efficient and readable, though it could be slightly more structured by separating the core purpose from the data breakdowns.

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 tool with one parameter, no output schema, and no annotations, the description is thin. It tells the agent what data is returned but not how to invoke it correctly (stock_code format), what the output looks like, or when to prefer it over sibling tools. The tool is simple, but the description still leaves important gaps for an agent deciding whether to call it.

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 0%, and the description does not explain the stock_code parameter beyond its name. The description implies the tool is per-stock, but it does not specify the expected format (e.g., numeric code vs. string, HKEX format, leading zeros). With only one parameter, the description should have compensated by explaining what stock_code means and how it should be formatted.

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 states a specific verb ('get') and resource ('CCASS custodian demographics for a stock') and enumerates the dimensions covered (type, province, gender, age distributions, HK letter/era breakdowns). It is clear what the tool returns, though it does not explicitly distinguish itself from siblings like get_registrar_analysis or get_allottee_profile, which may also relate to shareholder/custodian data.

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?

No guidance is given on when to use this tool versus alternatives. The sibling list includes several potentially overlapping tools (get_registrar_analysis, get_allottee_profile, get_stock_overview), but the description does not mention any of them or provide selection criteria. The only implied usage is that it applies to a stock identified by stock_code.

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