btcpay-mcp

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

With no annotations provided, the description carries the full burden. It adds valuable context about the data source ('BTCPay's configured rate provider') and timeliness ('current'), but omits operational details like caching behavior, rate limits, or authentication requirements.

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 'Args' and 'Returns' sections. Every sentence provides value—defining the operation, parameter format, and response source without redundancy or fluff.

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 simplicity (single optional parameter) and existence of an output schema, the description is appropriately complete. It covers the parameter semantics missing from the schema and identifies the rate provider, though it could explicitly note that the parameter is optional.

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%, requiring the description to compensate. The 'Args' section effectively documents the currency_pair parameter with format examples ('BTC_USD', 'BTC_EUR') and default value information, significantly augmenting 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 ('Get') and resource ('current BTCPay exchange rate') with scope ('for a currency pair'), effectively distinguishing it from sibling tools focused on invoices, payments, and wallets.

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?

While the description doesn't explicitly state 'when to use' rules or alternatives, the specific purpose makes implied usage clear. However, it lacks explicit guidance on prerequisites or when to prefer this over other data sources.

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