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

While annotations already indicate readOnlyHint=true, the description adds value by detailing return contents ('inputs, outputs, confirmations, and block hash') and reinforcing the mainnet scope. It does not contradict annotations and provides useful behavioral context beyond the structured metadata.

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 front-loaded with the primary action and scope, followed by return details. No redundant information 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?

For a simple single-parameter read-only lookup with no output schema, the description sufficiently covers purpose, scope, and return content. It is complete enough for an agent to select and use the tool correctly.

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 for txid is 100% with a full description. The tool description adds no new parameter semantics beyond mentioning 'by txid.' Baseline 3 is appropriate since the schema already fully documents the parameter.

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's function: 'Get full transaction details by txid on Bitcoin mainnet.' It identifies the specific verb (Get), resource (transaction), input (txid), and network scope (mainnet). This distinguishes it from sibling tools like btc_testnet_get_transaction and other chain-specific lookup tools.

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 context via 'on Bitcoin mainnet,' suggesting it's for mainnet transactions. However, it does not explicitly state when not to use it or name alternatives (e.g., testnet variant). Guidance is present but not exhaustive.

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