get_btc_account_balance

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

Annotations already set readOnlyHint=true, but description adds detailed behavior: walks pairing cache, fans out to indexer, skips empty cache entries, returns per-address breakdown. No contradictions.

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?

Single paragraph front-loaded with 'READ-ONLY'. Dense but efficient, every sentence adds value. No redundancy.

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?

Covers purpose, caching mechanism, output details, dependencies, and troubleshooting. For a tool with one parameter and no output schema, this is complete.

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 coverage is 100% with a detailed parameter description. The tool description reinforces the parameter meaning with additional context about cache staleness and pairing, but the schema already explains it well.

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 sums on-chain balance for a Ledger Bitcoin account index using cached addresses. It distinguishes from siblings like rescan_btc_account and pair_ledger_btc by specifying when to use them instead.

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?

Provides explicit guidance: call rescan_btc_account if cache is stale, only re-pair when funds may have landed past the gap window. Also notes 'pure indexer fetch, no Ledger needed' indicating safe usage.

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