session_open

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

Annotations only supply readOnlyHint=false and destructiveHint=false, so the description carries most of the behavioral burden and does so well: it clarifies that this is connect-only and that attach defaults to read-only. It also discloses that takeover "Ends that PowerView's session", which is a destructive side effect worth knowing about even though destructiveHint is false.

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?

The purpose is front-loaded in the first sentence and the mode details are cleanly separated. Minor waste from restating the ask-the-user warning that also appears in the access parameter text, and the trailing installed-targets note reads like runtime context rather than tool documentation.

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 six optional parameters, no required fields, and no output schema, the agent still gets no hint about what the call returns, such as a session handle that later sibling calls (session_status, session_close) presumably need. Everything about how to invoke the tool, including the risky takeover path, is covered.

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 coverage is 100%, so the baseline is 3, but the description adds real meaning beyond the schema: what each connection mode actually does, that sim is licensed by the probe when one is free, and that no installed targets were found, which warns the agent that the default target of arm may not resolve. Port and serial are left to the schema, which is acceptable at full coverage.

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?

"Start or join a TRACE32 PowerView" gives a specific verb and resource, and the follow-up clause "Connects only: it does not reset, download or run" draws a hard line between this tool and siblings like run, command, or script. The three connection modes further sharpen what kind of connection is being opened.

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?

Each mode (usb, sim, attach) is given an explicit situation in which it applies, including the licensing condition for sim. The attach guidance goes further, telling the agent to open read-only and look first, and to ask the user before requesting control.

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