Derive MCP

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

With no annotations provided, the description carries full burden but only states what data is retrieved without behavioral details. It doesn't disclose pagination behavior (implied by page/page_size), rate limits, authentication needs, or error handling, which are critical for a historical data tool with multiple parameters.

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 a single, efficient sentence that front-loads the core purpose without unnecessary words. Every part earns its place by specifying data type, historical nature, and timestamp inclusion.

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 (5 parameters, no output schema, no annotations), the description is incomplete. It lacks details on return format, pagination behavior, error cases, and how it differs from similar historical tools, making it inadequate for full 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?

Schema description coverage is 100%, so the schema fully documents all parameters. The description adds no additional meaning beyond implying timestamp filtering and 'index prices' context, which is already covered by parameter descriptions. Baseline 3 is appropriate as the schema handles parameter semantics.

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 as 'Get historical spot price feed data (index prices) with timestamps,' which specifies the verb ('Get'), resource ('historical spot price feed data'), and scope ('with timestamps'). It distinguishes from siblings like get_ticker (current prices) and get_trade_history (trades), but doesn't explicitly mention these alternatives.

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 historical index price data, suggesting when to use it versus real-time tools. However, it lacks explicit guidance on when not to use it or direct alternatives like get_funding_rate_history for funding rates, leaving some ambiguity.

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