kde_session_launch

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

Annotations only declare openWorldHint=true and destructiveHint=false. The description adds a genuinely useful behavioral fact beyond them -- 'no shell is used', i.e. argv is exec'd directly with no shell expansion or metacharacter interpretation. It is silent on whether the call blocks until exit, whether the process survives session stop, and whether output/PID is returned, which matters for a launch tool.

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?

One short sentence, front-loaded with the action, with the key safety qualifier attached by a semicolon. Zero filler and nothing buried.

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?

For a two-parameter tool with no output schema, the definition covers invocation well but leaves the agent without the return contract: no PID, exit status, or blocking behavior is described, and the schema cannot supply it since there is no output schema. Adequate to call, incomplete to reason about the result.

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 50%: session_id is documented but argv is not described at all. The description compensates by making clear that argv is an executable-plus-arguments vector passed without a shell, which tells the agent that argv[0] is the program and that quoting/globbing must not be relied on. That is real semantic value beyond the raw array schema.

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: launching an executable with argv inside a managed private KWin session. That is unambiguous and cannot be confused with the sibling session lifecycle tools (create/list/show/stop/use), though it never explicitly contrasts itself with them.

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: the required session_id and the phrase 'managed private KWin session' hint that a session must exist first, and the schema description points at kde_session_create/kde_session_list. There is no explicit when-to-use statement, no prerequisite ordering, and no note on what to do if the session has been stopped.

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