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

With no annotations, the description carries the full burden. It usefully discloses a site-wide shared cache, instant cache-hit returns, and token savings — real behavioral context. However it omits error behavior (dead links, JS-rendered pages), truncation signaling when max_chars is hit, and any rate limits or auth constraints.

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?

Two short sentences, front-loaded with the core action, then the caching caveat. No filler. Slightly terse — a few more words on truncation would not hurt, but nothing is wasted.

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?

No output schema exists, and the description does not state what the return looks like beyond '正文' — e.g. whether truncation is flagged or how non-HTML content is handled. For a simple 3-param fetch tool this is minimally adequate but leaves real gaps around failure and truncation.

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%, so url, force, and max_chars (with default 12000 and cap 120000) are already fully documented in the schema. The description's cache remark loosely relates to force but adds no syntax or format detail. 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+resource: 读取网页正文 (read webpage body text). Sibling tools (clock_now, memory_*, text_slice) are unrelated, so no differentiation is required. The purpose is unambiguous, though it doesn't specify what '正文' excludes (ads, nav, comments).

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 guidance on when to use this tool versus alternatives, nor on when to set force=true (e.g. stale content, suspected updates). The cache note hints at cost tradeoffs but never frames a decision rule. Usage is only implied by the verb.

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