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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint and non-destructive, so the safety profile is fully covered. The description adds value by enumerating the returned fields (title/link/score/comment count), but says nothing about result ordering (relevance vs points), pagination beyond hitsPerPage, or rate limits — modest gaps for a read-only search.

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 compact clauses with the resource, output fields, and a usage example front-loaded; nothing is padded. The inline example is mildly redundant with the schema's examples array, keeping it from a 5.

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 no output schema, the description usefully lists the returned fields, which is the key missing piece for a read-only search. An agent can call it correctly from what is provided; only result-ranking and pagination semantics remain unspecified.

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 all three parameters are documented in the schema, and the description's example duplicates the schema's own example. Baseline 3 applies since the description adds no new parameter meaning such as valid tag values or the default/max for hitsPerPage.

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 (搜索 Hacker News 科技资讯与讨论) and names the return fields (标题/链接/热度/评论数), so the agent knows exactly what it retrieves. It does not explicitly contrast with sibling search tools like stackoverflow_search or github_search, but the resource distinction is self-evident.

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?

Usage is only implied by the tool name and resource — 'search Hacker News' for tech discussions. There is no statement of when to prefer this over blog/web search via web_fetch, and no mention of the tags filter's role in narrowing by content type.

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