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

Annotations already cover the safety profile (readOnlyHint=true, destructiveHint=false), so the bar is lower. The description adds useful context: this is a legacy alias kept for compatibility, and it warns that the return format differs from fetch. However, it never specifies how the return shape actually differs, which is the key behavioral fact an agent would need to reliably parse the response.

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?

Three sentences, each earning its place: legacy status, function with the format caveat, and routing to fetch. Front-loaded with the deprecation warning before any promise of functionality. Slightly wordy in the opening parenthetical but still efficient.

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?

For a deliberately deprecated shim with one fully-documented parameter, read-only annotations, and simple behavior, the description tells an agent everything needed to decide whether to call it or route to fetch. The main gap—unspecified return format—is mitigated by the strong directive to use fetch for new work.

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 description coverage is 100%—the single url parameter is fully documented ('ページの URL かパス（日本語のままでも可）'). The description adds no parameter-level meaning beyond the schema, so the baseline of 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?

The description states a specific verb+resource: it returns the page body (

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 explicitly tells the agent when NOT to use this tool: '新しく使うときは fetch を使ってください' (use fetch for new usage). It also explains the only legitimate context—existing connections from before the rename. This is explicit when/when-not guidance naming the alternative.

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