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

Annotations cover the safety profile (readOnly, idempotent, no destruction), and the description layers on substantial behavioral context beyond them: emission schedule (50 LAX halved every 210,000 blocks), fee computation, the 100-block coinbase maturity rule, and the 500-transaction cap on fee reporting. This is exactly the domain context annotations cannot express.

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?

Front-loaded with the core definition and dense but purposeful throughout – every clause (subsidy schedule, fee formula, maturity, 500-tx cap) earns its place. Slightly long as a single run-on sentence, which costs some scannability.

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 no output schema, the description carries the full burden of describing return values and does so thoroughly: reward composition, units (wei and LAX), coinbase address, height/era, and maturity status. Nothing an agent needs to interpret the result is missing.

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 single 'block' parameter (number, hash, or 'latest') is fully documented in the schema. The description adds no syntax or format detail about the parameter, so the baseline 3 for high schema coverage applies.

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 exactly what the tool returns: the miner's earnings for a block, decomposed into subsidy, transaction fees, coinbase address, height/era, and maturity. The resource (block reward) is distinct from siblings like get_block, mining_stats, and supply_info, so an agent can select it without reading the schema.

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?

Usage is implied by the purpose – you call it to inspect the reward of a specific block – but there is no explicit when-to-use, no prerequisites, and no naming of alternatives (e.g., mining_stats for aggregate data). Adequate but with a clear gap.

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