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

Annotations already declare readOnlyHint=true, destructiveHint=false, idempotentHint=true, and openWorldHint=false. The description adds useful behavioral context by naming the data source (Yahoo Finance via yfinance) and stating no API key is required, but it does not discuss caching, rate limits, or output freshness.

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 front-loaded with the core purpose, then efficiently organized into use cases and holder_type options. It is short, readable, and every sentence contributes useful 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?

An output schema exists, so return-value explanation is not required. However, the underlying parameter object is complex and the description only covers the primary stock ownership use case, leaving advanced filtering and caching parameters undocumented for the agent.

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 reported as 0%, so the description must compensate, but it only explains holder_type options and only implicitly covers symbol. It does not explain the many other nested parameters such as wholesaler_ids, source_resource_id, exclude_fillers, or additional_display_fields.

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 gives a clear verb and resource: fetch ownership data for a stock, covering institutional holders, mutual fund holders, and insider transactions. It does not explicitly differentiate itself from the related sibling Get13FHoldings, but the scope is otherwise specific and understandable.

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 includes an explicit 'Use this tool when' list that gives concrete scenarios: checking institutional/fund ownership and insider buying or selling. It lacks when-not guidance and does not name alternatives such as Get13FHoldings for SEC 13F filings, so it is clear but not exhaustive.

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