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

Annotations already declare read-only, idempotent, non-destructive, and closed-world behavior. The description adds substantial context beyond annotations: computation method, default 1W window, through dates, fund counts, streak and N-PORT months, and weekly Monday-to-Friday report behavior.

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 and front-loaded, with the core purpose stated first, then mode-specific behavior. It is long and the second sentence is heavy, but most detail earns its place because the schema has no parameter descriptions.

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 output schema and zero schema description coverage, the description does a strong job explaining both return modes, default window, filters, and caveats like through dates. The main gap is the undocumented limit parameter.

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 coverage is 0%, so the description must carry parameter meaning. It explains ticker, window values and default, and the desk/category/issuer filters, but does not describe the limit parameter's effect.

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 resource and computation: ETF fund flows as published by ETFIQ, computed from daily shares outstanding change times NAV. It clearly distinguishes the with-ticker and without-ticker modes, so an agent can understand exactly what the tool returns.

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 clearly explains when each mode applies: with ticker for one fund's multi-window flows, without ticker for rankings and the latest weekly report. It also names filter dimensions, though it does not explicitly compare this tool to sibling ETF tools or state exclusions.

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