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

Annotations already establish that this is a read-only, non-destructive, closed-world operation. The description adds real context beyond them: the default target is the latest draft unless 'live' is set, and the capture reflects what visitors see rather than an editor view. It says nothing about latency, build state, or failure modes for unpublished sites.

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 primary use case and followed by the return value and default behavior. No filler, though the reflexive 'yourself' is slightly awkward phrasing.

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?

With an output schema present and 80% parameter coverage, the description does not need to explain return shape; it still usefully states that a picture is returned. What is missing is minor — whether unpublished drafts always resolve, or whether it works on sites outside the user's account.

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 80%, so the schema already explains site_id, path, device, full_page and live. The description's draft-vs-live and desktop/phone framing largely restates the schema and covers no additional parameter nuance, so the baseline 3 applies.

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 uses a concrete verb ('look at', i.e. capture a picture) on a specific resource (one of the user's WebTwizz sites) and states what comes back ('a picture of a page as visitors see it'). It does not distinguish itself from the sibling show-preview, so it falls short of a 5.

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 gives clear use cases — checking a change, reviewing the design, comparing against what the user asked for — which tell an agent when this tool is the right choice. There are no explicit exclusions or pointers to alternatives such as show-preview.

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