Analyze ETF

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

Annotations already declare readOnlyHint=true and openWorldHint=true. The description adds meaningful context beyond them: it is free, it summarizes what is returned (score, verdict, per-metric values, analysis link), and it warns that data coverage is mostly limited to US-listed funds.

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?

Two sentences, front-loaded with the core action and then the coverage caveat. The parenthetical metric list is dense but earns its place by revealing the scoring criteria; it is slightly long but not padded.

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, the description compensates by describing the return payload (score, verdict, metric values, link). Combined with the US-listing caveat, an agent has enough to call it correctly; only failure/edge-case behavior for non-US or invalid tickers is left unaddressed.

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 100% and the single 'symbol' parameter is fully documented with format examples in the schema. The description adds nothing about the symbol argument, so the baseline 3 is appropriate.

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 (analyze/scores) and resource (US-listed ETF), and enumerates the actual checklist dimensions used, so an agent knows exactly what output shape to expect. Naming the ETF scope implicitly separates it from the sibling analyze_stock.

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?

Clearly signals cost ('Free analysis') and states the applicability boundary ('Fund stats are usually only available for US-listed ETFs'). It stops short of explicitly routing stock queries to analyze_stock, so the when-to-use-this-vs-sibling condition is inferable rather than stated.

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