drag

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

No annotations are provided, so the description carries the full burden. It does disclose a real behavioral trait beyond the schema — movement follows a 'human path' (interpolated, not teleport) and units are CSS pixels matching screenshot output. However, it says nothing about whether the target must be scrolled into view, what happens if both ``index`` and ``x``/``y`` are omitted, whether the drag waits/settles after release, or what ``include_snapshot`` changes in the response.

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 core mechanic before the use cases and the aiming tip. It inlines parameter names in backticks so each reference is unambiguous, and no sentence is 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?

An output schema exists, so return values need not be explained, and the description covers the gesture, units, targeting, and the key slider use case — enough to invoke correctly. The remaining gaps are the unmentioned ``include_snapshot`` flag and the unresolved targeting ambiguity when neither ``index`` nor ``x``/``y`` is supplied, which matters for a state-mutating tool with zero annotation coverage.

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 coverage is 0%, but the description compensates well: it explains ``index`` (element), ``x``/``y`` (page point), ``dx``/``dy`` (CSS pixel offsets, with dy defaulting to 0 implied by 'move by (dx, dy)'). The gap is ``include_snapshot``, which is never mentioned, and the implicit rule that you target either an element or a point but not both is left unstated.

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 first sentence gives a precise verb sequence (press, move, release), the two targeting modes (element ``index`` or page point ``x``/``y``), and the travel vector in CSS pixels. It is unmistakably distinct from siblings like click_at (single point press) or screenshot (capture only), and an agent can tell what the tool does without opening 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?

It names concrete use cases ('slide to verify', puzzle sliders, range controls) and gives an explicit prerequisite workflow: aim the knob with `screenshot()` first. It also gives the special-case rule that for puzzle sliders ``dx`` is the piece-to-gap distance. It stops short of saying when NOT to use it (e.g. simple clicks or scrolling), so not a 5.

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