FinanceKit MCP

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

Annotations already declare readOnlyHint=true, indicating a safe read operation. The description adds valuable behavioral context beyond annotations by specifying what data is returned (expirations, strikes, volumes, open interest, implied volatility, greeks) and clarifying the default behavior when expiration is not specified ('nearest is used'). It doesn't mention rate limits or authentication needs, but provides useful operational details.

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 efficiently structured in two sentences: the first states the purpose, and the second details the return behavior. Every sentence adds value without redundancy, making it easy to parse and front-loaded with essential information.

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 tool's moderate complexity, rich annotations (readOnlyHint), and the presence of an output schema (which handles return values), the description is complete enough. It covers purpose, data returned, and default behavior, leaving no critical gaps for agent understanding.

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?

With 100% schema description coverage, the schema already fully documents both parameters (symbol and expiration). The description adds minimal semantic context by mentioning that expiration can be 'empty for nearest,' which is somewhat redundant with the schema's 'leave empty for nearest.' Baseline 3 is appropriate as the schema does the heavy lifting.

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 clearly states the specific action ('Get options chain') and resource ('for a stock'), distinguishing it from siblings like stock_quote or price_history by focusing on options data rather than stock prices or historical data. It specifies both calls and puts, making the purpose unambiguous.

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 implies usage for retrieving options data, but doesn't explicitly state when to use this tool versus alternatives like stock_quote for basic stock info or technical_analysis for technical indicators. No exclusions or specific contexts are provided, leaving usage somewhat open to interpretation.

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