What this Mac can do

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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description's added content is mostly an enumeration of what gets reported, which the output schema already conveys; it discloses no auth needs, cost, or side effects beyond that.

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 opening is front-loaded well, but 'Call first when unsure' appears twice in near-identical sentences and the following clause repeats the enumeration already given. The redundancy costs space without adding new information.

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 zero-parameter, read-only probe with an output schema and full annotations, the definition covers when to call it and roughly what it reports. Return-value detail is legitimately left to the output schema.

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?

The tool takes no parameters, so there is nothing for the description to disambiguate. Baseline 4 applies; it adds no misleading parameter guidance.

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?

The description names a concrete diagnostic scope: routes, GUI session, installed apps, and Keynote slide-op status, so an agent knows it reports machine capabilities rather than performing document work. It is distinguishable from siblings like iwork_metadata or iwork_verify_format, though the phrasing is loose and the enumerated items read as output contents rather than a crisp verb+resource statement.

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?

It gives an explicit trigger ('Call first when unsure what this machine can do') and an explicit exclusion ('Not needed before plain reads of .numbers or .key files'). An agent can decide whether to call it without opening any schema.

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