Derive 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 mentions 'real-time' data but doesn't disclose behavioral traits like rate limits, authentication requirements, whether the data is cached, error conditions, or response format. For a real-time data tool with zero annotation coverage, this leaves significant gaps in understanding how it behaves.

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 ('Get real-time ticker data for a single instrument') and appends key details (data fields). Every word earns its place with no redundancy or fluff, making it highly concise and well-structured.

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 complexity of real-time financial data, no annotations, and no output schema, the description is incomplete. It lists data fields but doesn't explain return values, error handling, or operational constraints. For a tool with no structured output or behavioral annotations, more context is needed to be fully helpful.

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%, with the single parameter 'instrument_name' documented in the schema. The description adds no additional parameter semantics beyond what's in the schema (e.g., no examples of instrument formats beyond the schema's 'e.g., ETH-20250131-3000-C, BTC-PERP, USDC'). With high schema coverage, the baseline is 3, and the description doesn't compensate further.

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 real-time ticker data') and resource ('for a single instrument'), distinguishing it from sibling tools like get_tickers (plural) and get_orderbook. It lists the specific data fields returned (bid/ask, last price, 24h volume, Greeks for options), making the purpose explicit and differentiated.

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 by specifying 'for a single instrument' and listing data fields, suggesting it's for real-time price/volume/Greeks queries. However, it doesn't explicitly state when to use this vs. alternatives like get_tickers (for multiple instruments) or get_orderbook (for depth data), nor does it mention prerequisites or exclusions.

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