Fill several fields at once in the DESKTOP grid browser (by pageId). One call instead of a web_type per field — noticeably faster on a long form, and it reports which field failed. NOT a device — there is no webpage_fill_form; on a real phone or tablet fill fields one at a time with webpage_type (by udid).
| Name | Required | Description | Default |
|---|---|---|---|
| fields | Yes | Fields to fill, in order | |
| pageId | Yes | Page ID from web_navigate |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
There are no annotations, so the description carries the behavioral disclosure burden. It clearly communicates that the tool performs a batch mutation, claims a performance benefit, and importantly states that it reports which field failed. A minor gap is that it does not specify what happens to already-filled fields when one fails, but the core behavioral traits are disclosed.
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 efficient sentences: the first states the core behavior and target, the second adds when it is beneficial and a key outcome, and the third routes around the main alternative. No filler or redundant restating of the schema.
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 2-parameter tool with full schema coverage and no output schema, the description gives enough context to select and invoke it correctly: target environment, pageId source, batching behavior, failure reporting, and mobile alternative. It could additionally describe the return format or partial-failure semantics, but those are not blockers.
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 description coverage is 100%, so the parameters pageId and fields are already documented in the schema. The description adds the context of multi-field batching and failure reporting, but does not need to explain parameter formats further; baseline 3 is appropriate.
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 states a precise action ('Fill several fields at once') on a specific resource ('DESKTOP grid browser (by pageId)'), making the tool's purpose immediately clear. It also explicitly distinguishes itself from the per-field web_type flow and from a device-level tool, so an agent can tell it apart from siblings like web_type and webpage_type.
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 guidance is explicit: use this tool for filling multiple fields in one call to be faster on long forms, and do not use it on a real phone/tablet — instead use webpage_type by udid. It also warns that there is no webpage_fill_form equivalent, reducing the chance of an agent searching for a nonexistent sibling.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Add one secure layer between your agents and this server.
The set contains near-identical duplicate families: web_* and playwright_* expose ~15 pairs of the same desktop-grid-browser operations (web_get_text/playwright_get_text, web_reload/playwright_reload), and screenshot/log/network/mock capabilities each have 5-8 entry points (device_screenshot vs android_mjpeg_screenshot vs ios_screenshot vs ios_fast_screenshot vs web_screenshot vs webpage_screenshot vs session_screenshot). Many individual descriptions carefully draw boundaries (devtools vs traffic, HID vs session), but an agent cannot reliably distinguish web_* from playwright_*, and ios_screenshot/ios_fast_screenshot/ios_mjpeg_screenshot blur together.
The prefix scheme is broken: Android functionality is split arbitrarily between android_* and device_* (device_screenshot vs android_mjpeg_screenshot), the desktop browser gets two parallel prefixes (web_* and playwright_*), and verbs vary across equivalents (device_navigate_url vs web_navigate vs ios_safari_navigate). session_* uses bare verbs (session_url, session_back), and the same concept gets different names (ios_clipboard_get_hid vs ios_get_pasteboard; device_screen vs ios_orientation).
333 tools is an extreme count by any measure — far beyond the 50+ threshold — and much of the bulk is duplicative (the web_*/playwright_* pairs alone double ~15 slots) or out-of-scope for a device-control server (TestRail, Jira, AzDO, agent memory, secret variables, feedback). Even granting that remote device control + test automation is a broad domain, this surface will devastate agent context budgets and is impossible to navigate coherently.
The core device-control and test-automation domain is remarkably thorough: Android and iOS each have full interaction, app-lifecycle, file, network/proxy, performance, crash, accessibility, recording, and replay coverage, with CRUD lifecycles for flows, suites, app uploads, TestRail cases, and visual-review baselines. Minor gaps exist at the margins — Jira/AzDO lack update/transition/comment operations, and iOS cannot open/close tabs — but the central workflows have no dead ends.
