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

Annotations already mark this as a non-destructive, read-only, idempotent, open-world operation. The description adds substantial behavioral context beyond that: average block times, wide interval variance, reorg marking, timeout return shape, and the special 90-second limit without HTTP sessions.

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 dense but front-loads the core behavior and then moves through return fields, timeout behavior, alternatives, and a usage tip. It is appropriately sized for a tool with waiting and timeout complexity, though it could be slightly easier to scan with clearer sentence breaks.

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?

There is no output schema, but the description lists the returned fields and describes the timeout and reorg cases. Together with the annotations and full schema coverage, an agent has everything needed to invoke and interpret the tool correctly.

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%, so the baseline is 3, but the description adds useful semantics: after_block defaults to the current head, and timeout_seconds has a server-dependent maximum of 90 seconds without HTTP sessions. This is meaningful beyond the schema's stated 1-600 range, though it does not deeply elaborate on edge cases.

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?

States a specific verb and resource: waits until the chain has a block above a given height, then returns that block. It clearly distinguishes itself from siblings like get_block by emphasizing the waiting behavior and defaulting to the current head.

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?

Explicitly says to use it to wait for a transaction's next confirmation and then check with get_receipt, and it names resource subscriptions as a better alternative for supported clients. It also explains what happens on timeout and that the tool can be called again.

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