get_block_by_num

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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint=false, covering safety. The description complements this by explicitly stating the return content ('block header and transaction list'), which is valuable given the absence of an output schema. It does not mention error cases or network behavior, but the bar is lowered by annotations.

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, front-loaded sentences with no filler. Every word adds value – it states the query mechanism and the expected result.

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 parameters and good annotations, the description covers the essential purpose and return type. However, it omits details about behavior for nonexistent block heights or invalid network names, which would make it fully complete. The return value description partially compensates for the lack of an output schema.

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 has 100% description coverage (both 'num' and 'network' have meaningful descriptions). The tool description adds no additional parameter semantics, so it meets the baseline of 3 for high schema coverage.

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 action ('Query') and the resource ('block by block height'), and specifies the return content ('block header and transaction list'). This distinguishes it from sibling tools like get_block_by_id, which query by hash.

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 usage context is implied by the phrase 'by block height' – the tool is for when you have a block number. However, it does not explicitly mention alternatives or exclusion criteria, leaving it to the agent to infer when to prefer this over other block-querying siblings.

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