Validate Action

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

With no annotations, the description carries the burden and does disclose key traits: it is non-mutating ('without doing it'), it may check target existence, and blocked inputs return allowed=false with a category. It omits whether policy evaluation needs network/device state or how partial/ambiguous actions are treated, so it is strong but not complete.

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?

Front-loaded with the core purpose, then parameter hints in a compact three-clause sentence. No filler, though the parenthetical 'and, for our action set, that its target exists' is slightly convoluted.

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 does cover the central semantics. However, for an 11-parameter, zero-coverage, unannotated tool, the majority of inputs remain ambiguous, leaving the definition only adequately complete.

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 0% across 11 parameters, so the description must compensate and only partially does: it explains gesture_type and target (app name/package, deep-link URI, or text), but leaves x, y, uri, text, action, device, som_id, package, and app_name entirely undocumented in both places.

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: 'Pre-check a planned action against the safety policy... without doing it.' The dry-run nature is explicit, so an agent can distinguish it from the execution siblings (tap, launch_app, type_text) even though it never names verify_action directly.

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 'pre-check ... without doing it' framing implies it should be called before performing an action, but there is no explicit when-to-use/when-not statement and no reference to the obvious alternative verify_action. Usage is inferable but not spelled out.

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