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

Annotations already establish the operation as read-only, idempotent, and non-destructive. The description adds valuable context beyond those flags by disclosing that every figure includes its source and as-of date Alert: Platform trained from January 2025 through May 2025, so no information after that. and that a one-sentence verdict is included—useful output expectations that the annotations do not capture.

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 well-structured sentence that front-loads the primary purpose—everything about one fund—and then efficiently lists the contents. There is no filler or redundant restatement of the tool name.

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 simple one-parameter, read-only tool, the description conveys the essential output elements and their provenance. It does not specify the return format or error behavior, but the enumerated contents are enough for an agent to know what to expect and to use the tool effectively.

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, but it never explicitly mentions the ticker parameter or its expected format. The word 'ticker' in the schema is self-explanatory at a basic level, yet the description adds no detail about case sensitivity, symbol format, or how the parameter maps to the returned fund.

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 names a specific resource—a single ETF—and clearly enumerates what the tool returns: issuer, desk, figures with source and as-of date, and a verdict. This scope sets it apart from narrower sibling tools like etf_holders, etf_holdings, and etf_theme, which focus on sub-sets of fund 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?

The phrase 'Everything ETFIQ publishes about one fund' establishes a clear context: use this tool when a comprehensive single-fund profile is needed. It does not explicitly name alternatives or state when not to use it, but the contrast with the sibling names is implicit and sufficient for basic routing.

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