Add desktop

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

Annotations already declare non-readOnly, non-idempotent, non-destructive, so the safety bar is partly covered; the description adds real value beyond them by disclosing the transient Mission Control UI flash and the return value (new number of Spaces after confirmation). It does not say whether the new desktop becomes the active Space, which is the main behavioral question an agent would have.

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?

Three short sentences, front-loaded with the action and placement rule, followed by the side effect and the undo path. Every sentence carries distinct information with no filler.

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 tool with no output schema, the description covers what is created, where it lands, the visible side effect, the return value, and the reversal path. Nothing an agent needs in order to invoke it is missing.

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 zero parameters, so the baseline is 4; there is no parameter meaning to add, and the description correctly avoids inventing any.

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 ("Create a new empty desktop") plus placement semantics ("at the end of the display the pointer is on"), and names the inverse tool remove_desktop, so an agent can separate it from siblings like switch_space or list_spaces without opening a 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 clear from context — call this when a new Space is needed — and the description explicitly routes the undo case to remove_desktop. It stops short of explicit when-not guidance (e.g. when to prefer apply_template or set_up_space instead of a bare desktop).

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