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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint, and destructiveHint=false, so the safety profile is fully covered without description help. The description adds the content shape (time, proposer, operations, explorer link), but says nothing about behavior for unknown heights, finality, or pagination of operations.

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?

Two short sentences, front-loaded with the resource and key, followed by the returned fields and a realistic example query. Nothing is redundant, though the quoted example is slightly informal compared to the terse first sentence.

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?

With an output schema present, the description needn't document return structure, and it correctly stays at the level of what the block contains. For a single-parameter, read-only lookup, the only real gap is behavior on invalid or future heights.

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 is 100% and the single parameter is documented as "block number" with a minimum of 0, so the schema carries the semantics. The description reinforces that lookup is by block height and the large example value (152,000,000) hints at scale, but adds no format or edge-case detail 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?

"One block by height" names a concrete resource (block) and the lookup key (height), and the field list (time, proposer, operations, explorer link) makes the return scope obvious. It is clearly distinct from sibling reads like get_tx or get_account, though it never explicitly contrasts with them.

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 example question "What happened in block 152,000,000?" implicitly signals the kind of user intent this tool serves, which is useful trigger phrasing. However, there is no explicit when-to-use statement, no exclusions, and no pointer to alternatives such as get_tx for individual transaction lookups.

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