etf_fund

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

With no annotations, the description carries the full burden. It only says 'Get', which implies a read operation, but provides no information about pagination, rate limits, authentication, or what happens on invalid tickers. It does not disclose any behavioral traits beyond the action itself.

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 one concise sentence without redundancy. It is appropriately front-loaded with the action, but could have added more detail in the same space; still, it earns a 4 for economy.

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 the large array of sibling ETF tools and no output schema, the description is too sparse. It fails to clarify what specific metrics and ratings are included, how this differs from etf_quote or etf_prices, or whether the data is real-time or historical. The tool is simple (one param) but the semantic context is under-specified.

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% for the single parameter 'ticker', and the schema already provides an example. The description adds no additional meaning about the parameter, so the baseline of 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?

The description states a specific verb ('Get'), a resource ('ETF fund information'), and includes a hint at content ('ratings and metrics'). This distinguishes it from price-focused siblings like etf_quote and etf_prices, though it doesn't name any alternatives explicitly.

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?

There is no guidance on when to use this tool versus the many sibling ETF tools (e.g., etf_quote, etf_prices, etf_holdings). The agent must infer that 'ratings and metrics' is the distinguishing factor, which is not explicitly stated.

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