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

No annotations are present, so the description carries full responsibility. It discloses the cost ($0.003 USDC) and the 'live' nature, but omits whether the operation is read-only, what happens on invalid block references, authentication requirements, or any rate limits. This is a significant gap for a tool with zero annotation coverage.

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?

A single sentence that front-loads the action and resource, then adds cost. There is zero waste and every word contributes to clarity.

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 tool with one optional parameter and no output schema, the description covers the purpose and parameter type. It misses usage guidance relative to siblings and error/edge-case behavior, but given low complexity and the cost mention, it is minimally adequate.

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 schema shows one optional parameter 'block' accepting string or integer. The description clarifies that the parameter accepts a number or a tag, which adds meaning beyond the schema's type union. However, it does not enumerate valid tags (e.g., 'latest', 'pending'), so coverage remains partial.

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 states a specific action ('Return') and a clear resource ('a live Base block header and transaction hashes') with the input dimension ('by number or tag'). It distinguishes itself from siblings like base_block_number (which returns only the number) and base_transaction (which returns transaction details) by its scope.

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 ('live', 'by number or tag') but does not explicitly state when to use this tool over alternatives like base_block_number or base_transaction. No exclusion criteria or mention of alternatives is provided, so guidance is minimal.

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