get_fund_data

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety and network scope are covered. The description adds genuinely new behavior: the tool raises an error for non-fund symbols. It stops short of noting rate limits, symbol-resolution behavior (ISIN), or whether missing data yields empty sections.

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 purpose and then the returned fields, followed by the negative case. No filler and nothing repeated from structured fields verbatim.

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?

An output schema exists, so return-shape explanation is unnecessary, and the description covers purpose, scope, and the error condition. The only gap is the absence of a redirect for non-fund symbols to a sibling tool, which an agent would have to infer from the sibling list.

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 100% – both `symbol` (ticker/ISIN) and `limit` (max holdings, default 25, max 100) are fully documented in the schema. The description's mention of 'top holdings' only loosely gestures at `limit` and adds no syntax or default info beyond the schema, so the baseline 3 applies.

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 and resource ('Get fund/ETF profile data for a Yahoo symbol') and enumerates the returned content: overview, asset-class and sector weightings, top holdings. The 'Fund/ETF-only' scope plus the explicit failure for stocks/crypto cleanly separates it from siblings like get_company_info, get_holders, and get_quote without naming them.

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?

Tells the agent exactly which inputs are valid (funds/ETFs) and which are not (stocks, crypto, which raise), which is a real routing signal. It does not name the alternative tool to use for a stock symbol (e.g. get_company_info), so the when-not case is covered but the redirect is left to inference.

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