pin_window

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

Annotations already declare readOnlyHint=false, destructiveHint=false, openWorldHint=false, so safety is covered. The description adds two genuinely useful traits: the operation targets the implicitly focused window (no selector parameter), and it is a toggle, meaning a second call reverts state and there is no way to set pinning explicitly. It omits return-value/confirmation behavior, but that is minor for this tool.

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 front-loaded sentence with zero filler; the effect and the target are both stated in the first few words.

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 action tool with annotations covering safety and no output schema, the description provides what an agent needs to call it. Only minor gaps remain (behavior with no focused window, whether success is reported).

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 per the baseline there is nothing for the description to disambiguate; the schema is fully descriptive in that it is empty. The description correctly signals the target is implicit rather than parameterized.

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 effect ('Toggle always-on-top pin') plus the exact target ('the focused window'), which is enough to distinguish it from siblings like toggle_float or toggle_fullscreen. It does not explicitly name those siblings as alternatives, so it stops 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 'focused window' — the agent must have a window focused, and the operation is a toggle, not an explicit on/off set. No guidance is given on when to prefer this over toggle_float/toggle_fullscreen or what happens when no window is focused.

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