snapshot

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

With no annotations provided, the description carries full burden for behavioral disclosure. It notes that indices are valid only until next navigation or snapshot, which is a key side effect, but omits other behaviors such as whether the snapshot is read-only, performance implications, or impact on page state.

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?

The description is brief (two sentences) and front-loaded with the action, but the omission of parameter details means it sacrifices completeness for brevity. A concise description should still cover essential usage details.

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?

Despite the tool having only one parameter and an output schema, the description is incomplete: it lacks parameter explanation, usage context, and when-not-to-use guidance. The validity note adds some value, but overall the description falls short of what an agent needs for proper invocation.

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 input schema has one parameter (viewport_only) with schema coverage at 0%, yet the description fails to explain its semantics or default behavior. Without any mention of the parameter, the agent cannot make informed choices about its usage.

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 clearly defines the tool's purpose: capturing an indexed accessibility tree snapshot of the current page. It uses a specific verb ('Capture') and resource ('indexed accessibility tree snapshot'), and the explicit temporal constraint on index validity (until next navigation or snapshot) differentiates it from sibling tools like click or navigate.

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 provides no guidance on when to use this tool versus alternatives, nor does it mention prerequisites or contraindications. An agent would lack context for deciding between snapshot and other tools like get_text or scroll.

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