Assistant didn't check for a local CLI before claiming a service integration was impossible

Description

Across a long troubleshooting thread about connecting a Readwise MCP connector (see #75954, #75955, #75958), the assistant repeatedly asserted it had no way to access Readwise from the session — pointing only to the (broken) MCP connector/registry tools and telling the user to use the Settings UI. At no point did the assistant check whether a local CLI tool for the service was already installed and usable via its general Bash tool access.

It turned out an already-authenticated Readwise CLI (readwise, npm package @readwise/cli@0.5.3) was installed at /opt/homebrew/bin/readwise the entire time, and a single readwise reader-list-documents --json call immediately returned real, live data (57k+ documents). This means the assistant's entire "I cannot connect to Readwise" framing across ~20 conversation turns was incorrect — a working path existed via Bash from the start, and several bug reports were filed (and time spent) based on the false premise that MCP was the only route.

Expected behavior

Before concluding that an integration/service is unreachable, the assistant should check for alternative access paths within tools it already has — e.g. which <service>, checking common package managers (brew list, npm list -g, pip show) for a CLI matching the service name — rather than assuming the MCP connector path is the only option.

Actual behavior

The assistant treated "no MCP tool available" as equivalent to "no way to access this service," across many turns, without ever running a basic which/CLI-discovery check via its own Bash access.

Repro steps

1. Have a CLI tool for some service (e.g. readwise) pre-installed and authenticated on the machine.
2. Ask Claude Code to use/connect to that service without mentioning the CLI.
3. Observe the assistant reasons purely in terms of MCP connectors/registry tools and concludes the task is impossible, without ever checking which <service> or package managers for a local CLI.

Environment

• Surface: Claude Code, session with Bash tool access.
• Related: #75954, #75955, #75958 (all filed based on the incorrect premise that no Readwise access path existed).