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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint false. The description adds behavioral context beyond these: it clarifies that the operation is free, requires no wallet, and that omitting chain (or passing 'all') queries every resolvable chain in one call. This extra detail about multi-chain behavior and cost is valuable beyond the structured 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 well-structured: the first sentence states the core purpose, the second paragraph gives concrete use cases, and the third covers parameter details. It is compact and front-loaded, with no filler. The chain list repetition is slightly redundant with the schema but serves as helpful inline reference.

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 correctly focuses on usage context rather than return format. It covers the key aspects: purpose, supported networks, use cases, default behavior, and non-functional properties (free, read-only, no wallet). This makes the tool fully understandable for an agent to select and invoke 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?

The input schema already documents the 'chain' parameter with a full enum and description, including the default behavior for 'all'. Schema description coverage is 100%, so the bar for added value is lower. The description reiterates the chain list and default behavior but adds little new semantic meaning beyond what the schema provides.

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 tool reads the current chain head (EVM block number or Solana slot) for a supported network. It uses a specific verb ('Read') and resource, and distinguishes it from siblings like network.transaction_status and market.crypto by focusing on block height.

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 provides clear use cases: confirming network progression before a transaction, correlating off-chain events with on-chain height, and choosing a safe starting point for log scanning. It does not explicitly name alternative tools, but the context implies when this tool is appropriate versus transaction status or token pricing tools, and notes it is free and read-only.

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