Avanza MCP Server

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 describes the return format in detail ('Chart data with: id, name, dataSerie, fromDate, toDate'), which adds value beyond the input schema. However, it doesn't disclose behavioral traits like rate limits, authentication needs, error handling, or whether it's a read-only operation (though 'get' implies read-only). The description is helpful but incomplete for behavioral transparency.

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 with clear sections (description, args, returns, examples) and front-loaded key information. It's appropriately sized for a tool with 2 parameters and detailed returns. However, some redundancy exists (e.g., repeating 'Returns' in both the description and a separate section), and the examples could be more concise, slightly reducing efficiency.

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 complexity (2 parameters, enum options, detailed output), the description is mostly complete. It explains parameters thoroughly, describes the return structure, and includes examples. Since an output schema exists (implied by 'Has output schema: true'), the description doesn't need to explain return values in depth, but it does so anyway. Minor gaps include lack of error handling or rate limit info, but overall it's sufficient for effective use.

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 fully. It provides detailed semantics for both parameters: 'instrument_id: Avanza fund ID from search results' and 'time_period: Time period for chart data' with a comprehensive list of enum options and explanations. This adds significant meaning beyond what the bare schema provides, fully documenting parameter usage and context.

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 tool's purpose: 'Get fund chart data with historical performance' and 'Returns time series data showing fund performance over the selected period.' It specifies the resource (fund chart data) and verb (get/retrieve). However, it doesn't explicitly differentiate from sibling tools like 'get_stock_chart' or 'get_fund_chart_periods', which would require a 5.

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 provides implied usage context: 'Perfect for visualizing fund NAV history and performance trends.' It suggests when to use the tool (for visualization of fund performance) but doesn't explicitly state when NOT to use it or mention alternatives like 'get_stock_chart' for stocks versus funds. No explicit guidance on prerequisites or comparisons with siblings is provided.

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