Computer Open Application

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

With no annotations, the description carries the full burden and does add real behavioral context: it reports the actual outcome across four states (opened / running-no-window / crashed / nothing-launched) and discloses an 8-second wait for a visible window. It stops short of covering idempotency (relaunching an already-open app) or elevation/admin requirements.

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 core action and the outcome-reporting promise are front-loaded, then platform specifics and the timeout follow in short clauses. The emphasized 'REALLY' is rhetorical but does signal that the tool verifies rather than merely launching; overall there is little waste.

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?

An output schema exists, so return shape need not be spelled out, and the description still names the outcome categories an agent will see. For a single-parameter tool with no annotations, this is nearly sufficient; the residual gap is failure/permission semantics and behavior when the target process already exists.

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 0%, so the description must compensate, and it does: the single `target` parameter is explained as an app name or full .exe path, with `start` semantics and two concrete example values. That is meaningful added meaning beyond the bare string type, though format edge cases (spaces in paths, arguments) are unaddressed.

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 (open) and resource (application) plus the accepted target forms (name or full .exe path). It is clearly distinguishable in practice from the screenshot/click/type siblings, but it never explicitly names or routes away from an alternative, keeping it just short of a 5.

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 implied by the verb and reinforced with platform guidance ('Windows: use `start` semantics') and concrete examples ('notepad' or 'chrome'). There is no statement of when not to use it, what to do if the app is already running, or which sibling to reach for instead, so guidance remains implicit.

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