[codex] narrow agent-reach skill web triggers

[vincent-peng]

Summary

• narrow Agent Reach skill activation so generic deep research, web search, web fetch, and arbitrary URLs prefer the agent native web tools
• keep Agent Reach routing for explicit Agent Reach requests and specialized platform/social collection
• update both Chinese and English skill templates plus search/web references so installed skills do not steer agents back to Exa/Jina for ordinary web tasks

Behavior impact

This is an intentional routing behavior change for generic web-only requests. After this PR, prompts such as "deep research X", "deep investigation X", "look this up", or a plain URL should use the host agent native web search / web fetch tools by default instead of Agent Reach.

Existing Agent Reach platform workflows remain covered when the user explicitly asks for Agent Reach or asks for supported platform/social collection, including Twitter/X, Reddit, Facebook, Instagram, XiaoHongShu, Bilibili, V2EX, LinkedIn/jobs, YouTube/podcasts, GitHub code search, Xueqiu, and RSS.

If a user still wants Agent Reach for a generic search fallback, they can say so explicitly, for example "use Agent Reach" or ask for multi-platform/social discussion.

Why

The previous skill frontmatter said Agent Reach was MUST USE for any research/search/look-up task and any URL. In skill-aware agents such as Claude Code and Codex, that can hijack ordinary web research away from the agent native web search/fetch tools even when no Agent Reach-specific platform is needed.

Validation

• uv run --extra dev python -m pytest tests/test_skill_command.py tests/test_cli.py -> 27 passed
• uv run --extra dev python -m pytest -> 196 passed
• rg -n "MUST USE|look up anything|look up/find anything|any web URL|shares any URL|shares any URL/link|research:|search: 搜|Web / code search|Web pages / articles|网页搜索/代码搜索|网页/文章/RSS|全网调研类任务|For broad research tasks|do a deep dive|search the web for|Read any web page|通用网页" agent_reach/skill -> no matches
• Fresh Codex smoke, generic request: Please do deep research on AI SEO market size. -> agent-reach=no
• Fresh Codex smoke, explicit request: Use agent-reach to search Twitter and Reddit ... -> agent-reach=yes

[moxxxskaifa]

78 行 skill 文档改动，窄化了 web 触发条件。

需要确认：

1. 改动后现有用户是否感受到行为变化？
2. 是否经过测试验证？

能贴一下测试输出吗？

[vincent-peng]

已确认，我也把 PR description 补充了行为影响和验证结果。

1. 行为变化：会有，但范围是有意收窄。普通 deep research / deep investigation / look this up / 单纯 URL 读取这类通用网页检索请求，现在应优先走宿主 agent 自带的 web search / web fetch，而不是自动触发 Agent Reach。显式说 use Agent Reach，或请求 Twitter/X、Reddit、Facebook、Instagram、小红书、Bilibili、V2EX、LinkedIn/jobs、YouTube/podcasts、GitHub code search、Xueqiu、RSS 等 Agent Reach 覆盖的平台/社交内容聚合时，仍会触发 Agent Reach。

2. 已做验证，测试输出如下：

uv run --extra dev python -m pytest tests/test_skill_command.py tests/test_cli.py
27 passed in 10.49s

uv run --extra dev python -m pytest
196 passed in 25.15s

rg -n "MUST USE|look up anything|look up/find anything|any web URL|shares any URL|shares any URL/link|research:|search: 搜|Web / code search|Web pages / articles|网页搜索/代码搜索|网页/文章/RSS|全网调研类任务|For broad research tasks|do a deep dive|search the web for|Read any web page|通用网页" agent_reach/skill
# no matches

额外用 fresh Codex session 做了两条 smoke：

Generic: "Please do deep research on AI SEO market size."
=> agent-reach=no

Explicit: "Use agent-reach to search Twitter and Reddit..."
=> agent-reach=yes

所以这个改动的预期效果是：避免 Agent Reach 抢走通用 web research/fetch；保留显式 Agent Reach 和平台型采集场景。

[Panniantong]

该 PR 假设所有宿主都自带 Web 搜索和抓取，并会移除 Agent Reach 现有 Exa 与 Jina 触发范围；这一产品前提不成立，会让无原生 Web 工具的 Agent 失去能力，因此关闭。