mouse_up

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

Beyond the annotations, the description discloses an important behavioral trait: the VM remains locked by this session and the agent must call vm_unlock when finished. It also clarifies that the tool may move the pointer before releasing. This is consistent with the annotations and adds real operational value.

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?

Two sentences, action first, lock warning second, with zero filler. Every piece contributes to correct invocation or lifecycle handling.

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 simple input tool with no output schema, the description plus schema coverage is nearly complete: it states the action, optional coordinate behavior, and the critical VM-lock postcondition. It does not explicitly mention pairing with mouse_down or behavior when no button is held, but these are minor gaps.

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 schema already documents x, y, button, and vm_name well. The description adds meaning to x/y by stating they are used for an optional movement before the release, which is not evident from the schema alone. The button parameter is self-explanatory via its enum and default.

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 opens with a specific action, 'Release a held mouse button', and adds the optional coordinate-move behavior. This clearly distinguishes it from siblings like mouse_down, qemu_mouse_click, and mouse_release_all by targeting a single button release.

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?

The description gives context by mentioning releasing a held button and the VM lock state, but it does not explicitly name alternatives or state when to prefer this over mouse_release_all or after mouse_down. The usage is implied rather than directly guided.

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