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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so the safety profile is covered. The description adds the important scoping note about internal visits and the date-range bound, but does not mention the 90-day maximum, default 30-day window, or pagination/return volume. With annotations carrying the safety burden, this is adequate but not rich.

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?

Two tight sentences: the first says what is returned, the second says the filtering options and the sibling escape hatch. Nothing is wasted and the front-loaded verb/resource framing is correct.

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 read-only list tool with no output schema and partial annotations, the description covers the main return fields and filtering, and points to get_session_timeline. However, it omits the 90-day cap, the default 30-day range, and any pagination/result-size expectation, which an agent needs to invoke it correctly.

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 25%: days, link_id and include_internal have no schema descriptions, and only the 90-day/days default hint is present. The description partially compensates by saying it filters by link and optionally includes internal visits, which maps to link_id and include_internal, but it ignores the days parameter and its boundaries. Baseline for near-miss coverage is around 2-3; the description earns a 3 for mapping two of three undocumented params.

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 clear verb (List) and resource (visits to this page), and enumerates the returned fields (device, start, duration, entry/furthest page, steps, source). It does not differentiate itself from the many other list_* siblings, but the domain object (visits/sessions) is specific enough to distinguish it from list_proposals or list_folders.

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?

Gives explicit scope (date range) and the ability to filter by link or include internal visits, plus routes the agent to get_session_timeline for per-step detail. It does not state when NOT to use it or name alternative list tools, but the sibling hand-off for individual steps is a concrete usage rule.

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