InsightSentry MCP

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

No annotations are provided, so the description carries the full burden. It compensates by disclosing the return structure: 'Returns {available_fields: string[], available_exchanges: string[], available_countries: string[], sortOrder: string[]}' and clarifies the data format ('All arrays are flat string arrays'). It does not mention rate limits or caching, but successfully documents the output shape.

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 front-loaded with purpose and efficiently structured. There is minor redundancy between the first two sentences ('Get available ETF sccreener parameters' vs 'Retrieve the list of available fields and parameters'), but subsequent sentences earn their place by documenting return types, array formats, and next steps.

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 absence of an output schema, the description comprehensively documents the return structure and data types. Combined with the workflow guidance (linking to screen_etfs) and the well-documented input parameter, the description provides complete context for this simple discovery tool.

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 input schema has 100% description coverage for its single 'filter' parameter, establishing a baseline of 3. The description does not add parameter-specific semantics, but none are needed given the comprehensive schema documentation.

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 explicitly states the tool 'Get[s] available ETF screener parameters' and 'Retrieve[s] the list of available fields and parameters for ETF screening.' It specifically mentions 'ETF' twice, clearly distinguishing it from sibling tools like get_stock_screener_params and get_bond_screener_params.

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 explicit workflow guidance with 'Next: use screen_etfs with these fields,' establishing the correct sequence (discovery before screening) and linking to the sibling tool screen_etfs. This clarifies that this tool is for metadata discovery, not the actual screening operation.

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