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

No annotations are provided, so the description carries the full burden. It discloses the pay-per-call cost ($0.005 USDC) and indicates the result is a 'header + summary' rather than a full block. However, it does not mention error behavior, rate limits, or what happens when an invalid number is provided or when 'latest' is omitted.

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 a single efficient sentence that packs the resource, selecting input, output fields, and pricing with no filler. Every part earns its place and the key info is 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?

For a single-parameter tool with no output schema, the description lists return fields (compensating for output schema absence) and pricing. It is slightly incomplete because it does not clarify the default for an omitted 'number' or behavior for invalid blocks, but overall it is sufficient for a basic call.

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 input schema already describes the single parameter 'number' with 100% coverage ('Block number or "latest"'). The description essentially restates the same information without adding format details or default behavior, so it adds little beyond the schema.

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 resource ('base block'), selection criteria ('by number or latest'), and enumerates the returned fields (hash, timestamp, tx count, gas used, base fee). This clearly differentiates it from sibling tools such as base_tx, base_gas, and polygon_block.

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 gives clear context (retrieve block header/summary data) but does not explicitly name alternatives or state when not to use this tool. An agent can infer usage from the listed fields, but there is no explicit routing guidance compare to siblings.

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