ブロックを読む

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

Annotations already declare readOnlyHint=true and destructiveHint=false, covering safety. Description adds behavior: returns header info and optionally first 50 transaction hashes (if include_transactions=true). Still, lacks details on error cases, network handling, or whether latest is resolved dynamically. Given read-only annotation, this is acceptable but not rich.

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?

Single sentence, efficient and front-loaded with the core information. No fluff. Would be 5 if it included a usage guideline, but given its simplicity, it's near-optimal.

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?

Tool is simple (3 optional params, read-only, no output schema). Description covers purpose and optional behavior (50-transaction limit). Could mention that network accepts URL, but that's in schema. With good annotations and full schema coverage, it's sufficiently complete for its simplicity.

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 covers 100% of parameters with descriptions. Description adds nothing beyond param names. It mentions '先頭 50 件' in include_transactions description, so schema already explains behavior. Baseline 3 is correct; the description does not need extra param info since schema is complete.

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?

Description clearly states: reads block header info and specifies exact fields (parent hash, time, gas used, transaction count). Differentiates from siblings like read_transaction, account_info, and call_contract by focusing on block-level data. Even without title/name details, the verb '返す' plus resource 'ブロックのヘッダ情報' makes purpose explicit.

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?

No explicit when-to-use or alternatives mentioned. The description implies usage for block header queries, but doesn't exclude cases like needing full transactions (which could be handled by read_transaction) or chain info (chain_info). Basic context given, but no guidance on choosing this over other sibling tools.

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