get_stock_fundamentals

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

With no annotations provided, the description carries the full behavioral burden. It discloses the data source (Finviz), the snapshot nature, and the approximate delay (~15-20 min), which are meaningful behavioral traits. It does not mention rate limits or auth requirements, but for a read-only single-ticker snapshot tool, the key behavioral context is present.

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 well-structured and front-loaded: purpose, return content, source, alternatives, and args. There is minor redundancy in repeating 'Finviz' and 'current snapshot' in the 'Data source' line, but overall every section earns its place and the length is appropriate.

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 one-parameter snapshot tool with an output schema present, the description is complete. It covers what the tool returns, the data source, the delay, the scope of fields, and the key alternative for historical data. Nothing an agent needs to invoke it correctly is missing.

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. It does so by documenting the ticker parameter with a clear definition and examples ('AAPL', 'BRK-B'), which adds format and usage nuance beyond the bare schema. The guidance is brief but sufficient for a single required parameter.

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 opens with a specific verb and resource: 'Get comprehensive fundamental data for a stock from Finviz.' It lists concrete coverage areas (valuation, profitability, balance sheet, ownership, technical indicators) and explicitly distinguishes itself from historical data tools by calling itself a current snapshot. This makes it easy to separate from siblings like get_financial_history and get_financial_ttm.

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 description clearly states when not to use this tool: 'For historical time-series data use get_financial_history or get_financial_ttm.' It also implies the use case—current snapshot fundamental data—through the delay and coverage wording. It does not explicitly compare against get_financial_snapshot or get_per_share_fundamentals, but the 'comprehensive' and '90+ fields' framing provides enough context for an agent to choose correctly.

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