Observe page

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

Annotations already mark the tool read-only, and the description adds meaningful context beyond that: changing scope resets the diff baseline, and secrets handling exposes only aliases, never values. The instruction to 'Respect truncation and frame metadata' is useful but slightly terse.

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?

Five compact sentences, with the core action front-loaded. Scope guidance, the diff-baseline caveat, truncation/frame caution, and secret-handling behavior are all relevant, and there is no 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?

With seven parameters, low schema coverage, and no output schema, the description must supply substantial context. It covers scope selection and diff behavior well, but leaves full/diff mode semantics and the return payload largely implicit. Adequate with clear gaps.

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 only 14%, so the description carries most of the parameter burden. It adds real meaning for selector and viewport_only, and hints at frame_id via frame metadata, but it never explains the mode full/diff choices, text_limit, or max_elements. This is partial compensation, not full.

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 opens with 'Read the page and mint a new snapshot_id', which is a specific action with a distinct output resource. It does not explicitly name a sibling alternative, but the snapshot_id concept and scope language make the tool's role clear.

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 concrete selection guidance: use a CSS selector for a root or viewport_only to reach controls beyond a truncated page. It also warns that changing scope resets the diff baseline, which is useful when deciding scope. It does not explicitly compare against sibling tools or state when not to use it.

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