launch

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

With no annotations, the description carries the full burden and does well: it discloses the return value (the resulting screen), the default state behavior (resumes where the app was left unless restart), and that grant pre-authorizes permissions such as camera or notifications. It omits failure modes and what happens when url is given without app, keeping it from a 5.

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?

A single dense sentence where every clause earns its place, but the nested parentheticals and semicolons make it harder to scan than a short bulleted breakdown would be.

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 four-parameter tool with no annotations and no output schema, the description covers inputs, return value, and state semantics adequately. Only edge cases (url without app, grant failure, restart side effects) are left unaddressed.

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 description coverage is 0%, so the description must compensate, and it does: app accepts any part of a name or an id, url is opened in the app given by app, restart controls fresh vs resumed state, and grant is illustrated with concrete permission values (camera, notifications). All four parameters gain meaning not present in the bare 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 ('Open') with two concrete resources (an app by partial name or id, or a url), plus what it returns (the screen the app shows). An agent can tell this apart from siblings like 'apps' or 'screenshot' without inspecting the schema.

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 description explains that a url can be opened inside a specific app and that restart forces a fresh start versus resuming where the app was left. It never names an alternative (e.g., 'apps' for listing) or states when not to use this tool.

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