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

With no annotations present, the description takes on the burden. It discloses the important behavior that omitting parameters returns the current chain tip and that the result is a summary with specific fields. It does not cover edge cases such as invalid heights or both parameters being provided, so behavioral transparency is adequate but not exhaustive.

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 sentences, front-loaded with the tool's output contents and immediately followed by usage guidance. Every phrase — fields returned, current-tip default, and when-to-use — carries meaning with no filler or repetition.

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 read-only tool with two optional parameters and no output schema, the description covers the key facts: what fields are returned, how to get the latest block, and how to target a specific height or hash. It lacks an explicit indication of the exact JSON shape or error behavior, but the listed fields give an agent sufficient understanding to invoke it.

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 100%, so each parameter (height, blockhash) is already documented in the schema with types and optionality. The description reinforces that parameters are optional and that height or block hash can select a block, but adds no new semantic details beyond the schema; baseline 3 applies.

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 identifies the resource as Bitcoin block summaries and explicitly lists the returned fields (tx count, size, weight, block time, confirmations), making the tool's purpose clear. It is distinct from sibling tools like btc_tx_lookup and btc_mempool_summary by focusing on block-level summary data. However, it lacks an explicit action verb, so it stops short of a top score.

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 includes a dedicated 'When to use' clause: querying how many transactions the latest block holds, or getting an overview at a given height or block hash. This gives clear contexts for invocation, though it does not specify when not to use the tool or name alternatives, so it earns a 4 rather than a 5.

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