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 and successfully discloses that the operation returns 'confirmed/unconfirmed balance' and specifies default behavior when the parameter is omitted. It does not cover error handling or authorization requirements, preventing a 5.

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 uses a structured docstring format (Args/Returns) with zero redundancy. Every line provides essential information: the first sentence establishes purpose, the Args section explains the single parameter, and the Returns line clarifies the output content.

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 (1 optional string parameter) and presence of an output schema, the description is appropriately complete. It covers the parameter semantics despite poor schema coverage and identifies the return data type (confirmed/unconfirmed) without needing to detail the full output structure.

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?

Despite 0% schema description coverage, the description fully compensates by documenting the `payment_method_id` parameter with a concrete example ('BTC'), explanation of what it references ('store's default BTC wallet'), and detailed default behavior ('Leave empty to use the first BTC-like method').

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 opens with a specific verb ('Get') + resource ('wallet balance') + scope ('for a payment method'), and explicitly qualifies it as 'on-chain wallet' to distinguish from the sibling `get_lightning_info` tool.

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 guidance through the parameter documentation (e.g., 'Leave empty to use the first BTC-like method'), but lacks explicit comparison to siblings like `list_wallet_transactions` or `get_store_payment_methods` to clarify when to query balance versus transaction history or method lists.

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