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

With no annotations, the description carries the full behavioral burden. It discloses the filtering behavior, the calculation windows, and even the likely outcome ('Most members do not beat the market'), which gives useful context beyond the bare 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 concise and efficiently front-loaded with the core metric. Every sentence adds value, and the external data source link is a useful reference without bloating the text.

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 there is no output schema and no annotations, the description covers the main calculation, qualifying criteria, interpretation, and data source. It is nearly complete, though it omits ordering, pagination, or what limit controls, which prevents a 5.

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%, so the description must compensate. It does explain min_trades ('members with at least min_trades priced purchases'), adding real meaning, but limit is left unexplained despite also being relevant to output size.

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 analytical goal: computing per-member 90-day returns versus the S&P 500, plus 30-day alpha and hit rate. This clearly differentiates the tool from sibling list/filing tools and identifies the resource and metrics it produces.

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 implies when to use it (when you need per-member alpha versus the market) and gives qualifying criteria (min_trades, full 90-day window). However, it does not explicitly mention alternatives or say when not to use it compared to sibling tools.

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