launch_app

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

Annotations already declare readOnlyHint=false, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description adds the useful fact that launching is implicitly deferrable, but it does not say what happens if the app is already running (idempotency) or whether an explicit launch changes session state. The headless data-loss caveat lives in the schema, not the description.

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 short sentences, zero filler, with the most decision-relevant information (you usually don't need this) front-loaded right after the purpose.

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 one-optional-boolean launch tool with no output schema and good annotation coverage, the description covers purpose, necessity, and alternatives. The only real gap is behavior when the app is already running, which matters for a mutate-session tool but is a minor omission.

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% and the single parameter carries a detailed description including the song-loss caveat, so the schema does the heavy lifting. The description only alludes to the parameter via "choose the mode," adding no format or default detail beyond what the schema already says. Baseline 3 applies.

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?

"Starts Bosca Ceoil Blue" gives a specific verb and resource, and the following clause explains the tool's role relative to the rest of the toolset. An agent immediately knows this is the app-launch tool and not a general-purpose action.

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?

Explicitly states that other tools launch the app on demand, so this is only needed "to choose the mode or to open the window before working." Both the trigger condition and the redundant case are named, which is stronger guidance than most definitions provide.

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