alpaca-mcp-server

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

Annotations provide readOnlyHint=true and openWorldHint=true, indicating safe read operations with potentially large datasets. The description adds valuable behavioral context beyond annotations: it explains the automatic start time computation when omitted, clarifies the 'limit' parameter applies across all symbols, and specifies timestamp sort options. No contradiction with annotations exists.

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 a clear purpose statement followed by detailed parameter explanations. Every sentence adds value, though the parameter section is somewhat dense. It's appropriately sized for an 8-parameter tool with complex interactions, but could be slightly more streamlined.

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 (8 parameters with interactions), 0% schema coverage, and the presence of an output schema, the description is remarkably complete. It thoroughly documents all parameters, explains behavioral nuances (automatic lookback, cross-symbol limit), and since an output schema exists, it appropriately omits return value details. No significant gaps remain 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 0% schema description coverage, the description fully compensates by providing comprehensive parameter documentation. It explains all 8 parameters, including their purposes, formats (e.g., RFC 3339, comma-separated symbols), default values, ranges (limit 1-10000), and interactions (how start omission triggers lookback). This adds substantial meaning beyond the bare schema.

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 ('Retrieve historical bid/ask quotes') and resource ('for one or more cryptocurrencies'), distinguishing it from sibling tools like get_crypto_latest_quote (real-time) or get_crypto_bars (OHLC data). It precisely defines what data is returned and for what asset class.

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 context through parameter explanations (e.g., 'When start is omitted...'), but doesn't explicitly state when to use this tool versus alternatives like get_crypto_latest_quote for real-time data or get_crypto_bars for OHLC bars. It provides operational guidance but lacks comparative sibling differentiation.

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