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

Annotations already declare readOnlyHint=true, destructiveHint=false, and idempotentHint=true, so safety is covered. The description adds meaningful behavior beyond annotations: sorting by portfolio value, exclusion of options, Chinese name fields, and the predecessor CIK behavior. It does not contradict annotations, and the added context enriches the agent's understanding without relying on the schema.

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 dense but each sentence earns its place: main purpose, data fields, sorting, naming, predecessor CIK, and alternatives. It is front-loaded with the primary function and avoids redundancy. Slightly long but not wasteful.

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?

With no parameters and an output schema present, the description covers all essential call-time information: what data is returned, sorting, edge case of source_cik, and pointers to sibling tools. It does not mention pagination or rate limits, but those are less critical given the tool's simplicity and the output schema's coverage.

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 tool has zero parameters, so the baseline is 4. There is nothing for the description to add beyond what the schema provides (which is empty). The description appropriately explains the data structure instead, which is not parameter-related. No issues.

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: 'list the curated list of superinvestors' with detailed data fields (portfolio value, positions, filing date, top holdings). It clearly distinguishes from siblings by mentioning get_institution and get_superinvestor_activity for different needs, so an agent can tell it apart.

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?

Explicitly directs when to use alternatives: 'Use get_institution(cik) for full holdings and get_superinvestor_activity for what they bought and sold in a quarter.' Also explains the source_cik caveat, leaving no ambiguity about when to use this tool versus siblings.

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