get_btc_balance

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

Annotations already mark it as read-only and idempotent; the description adds that it uses mempool.space's public API by default, configurable via env var or userConfig, and details the return structure. This provides significant behavioral context beyond the annotations.

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 two concise sentences. The first sentence delivers the main purpose and return details, and the second adds backend configuration info. No unnecessary words, efficiently front-loaded.

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?

Despite no output schema, the description enumerates all return components (sats/BTC confirmed+mempool, address type, tx count) and explains backend configurability. For a simple read tool, this is complete and sufficient for agent use.

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?

The single parameter 'address' has a schema description that lists accepted formats; the tool description reiterates these formats and adds the constraint that testnet/signet is not supported. While it adds value, the parameter is simple and the schema already covers the key 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 it fetches confirmed and mempool balance for a single Bitcoin mainnet address, specifying return components (sats, BTC, address type, tx count). This distinguishes it from sibling tools like get_btc_balances which likely handle multiple addresses.

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 mentions it is read-only and mainnet-only (testnet/signet rejected), providing some usage constraints. However, it does not explicitly guide when to use this tool versus siblings like get_btc_balances or get_btc_account_balance, leaving comparison to the agent.

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