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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so safety is covered. The description adds genuine context beyond them: data source (Yahoo Finance via yfinance), that no API key is required, and the flattened multi-ticker output layout.

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?

Front-loads the core capability, then uses a compact bulleted 'when to use' block and a symbol-format example. Every element earns its place; the only minor slack is the example duplicating the schema.

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 an output schema present, return values need not be explained, and the description still supplies source, format, and selection guidance. Coverage is solid for a read-only lookup tool, though it ignores the auxiliary filtering params entirely.

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?

The description restates the symbols format ('AAPL MSFT GOOGL' / 'SPY,QQQ,IWM'), which the schema already documents verbatim, adding no new meaning. The many other params (period, interval, wholesaler_ids, source_resource_id) are documented in the schema but not addressed in the description, so it neither compensates for nor extends them.

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+resource (fetch OHLCV price history) and scopes it explicitly to multiple tickers 'in a single call,' which cleanly distinguishes it from the sibling GetPriceHistory for a single symbol. It also names the return shape (flattened table with 'AAPL_Close', 'SPY_Volume' columns).

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?

Provides an explicit 'Use this tool when:' list covering cross-security comparison, correlated portfolio data, and correlation matrices. It gives clear positive selection criteria but never names the single-ticker sibling (GetPriceHistory) as the alternative, so the boundary is implied rather than stated.

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