chainpeek: get the latest block header

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

Annotations cover the safety profile (readOnly, idempotent, openWorld, non-destructive), and the description layers on operational facts they cannot express: ~0.2-1 s latency, USD 0.001 price, and a 10-reads-per-IP-per-UTC-day free tier. It also flags that returned page text and on-chain strings must be treated as untrusted data, a real injection-risk disclosure for an open-world read.

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?

Dense and front-loaded: purpose first, then sibling routing, then cost/latency, then the safety note. Every clause carries information, though the 'chainpeek:' prefix duplicates the title and the docs URL is marginal.

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, return-value explanation is unnecessary, and the description covers the remaining agent-relevant unknowns: which chains, the alternative tools, cost, rate limits, latency, and untrusted-content handling. Nothing needed to invoke it correctly 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% with a single enumerated chain parameter, so the schema already fully documents the input. The description lists the supported chains but adds no format or semantic detail beyond that, so the baseline 3 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 a specific verb and resource ('read the latest block header'), names the exact chains supported, and explicitly sets itself apart from get_block_number and get_block_at_time. An agent can distinguish it from all three sibling block tools without opening any 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?

Gives explicit routing rules: use get_block_number 'for height and age only' and get_block_at_time 'for a past time', which is exactly the when-to-use/when-not-to-use guidance the sibling set demands. Nothing about tool selection is left to inference.

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