Time of day

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

Annotations already cover readOnly/idempotent/non-destructive/closed-world, so the bar is low, and the description adds real context: the 400-day range cap, dates in the project time zone, and a provenance caveat that event names, paths, property values, etc. are raw visitor-supplied text 'reported as it arrived.' That provenance warning is genuinely useful beyond the structured fields.

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 purpose sentence is front-loaded and each paragraph carries distinct information (what it is, parameter sourcing/constraints, data provenance). Slight waste in the awkward phrasing 'The visits of the range by the weekday,' but overall it is tight and well-ordered.

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 report with full schema coverage and annotations, the description covers purpose, constraints, and data caveats. With no output schema, it conveys the grouping shape (weekday × hour) but does not describe the returned fields or metrics, a minor remaining gap.

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 100%, so the baseline is 3. The description restates some schema facts (to at most today, project id from list_projects) but does add two details not in the schema: the project time zone and the 400-day maximum range. That is modest added meaning over the already-complete schema.

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 names a concrete resource and breakdown dimensions: 'The visits of the range by the weekday and the local hour they started.' An agent can infer this is a time-of-day visit report, not a raw list. However, it never distinguishes itself from siblings like visits, overview, or engagement, which also surface visit data.

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?

Usage is only implied by the report's nature; there is no explicit 'use this when you want X, otherwise use visits/overview' routing. It does provide useful setup context (project id and today come from list_projects), but that is parameter sourcing rather than when-to-use guidance.

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