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

With only readOnlyHint in annotations, the description carries the transparency burden and does well: it identifies two distinct data sources (Umami browsers vs server-side all_visits), explains that assistants don't run scripts, and lists the event funnel metrics. It adds meaningful behavioral detail without contradicting the read-only annotation.

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 front-loads the purpose and restriction, then delivers details in labeled sections ('people', 'all_visits') and closes with a summary instruction. It is dense but not verbose; nearly every clause carries useful information. Could be more structured, but it is efficient.

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 simple optional-parameter analytics tool, the description covers the main metric groups, data provenance, and how to present results. It omits an explicit statement of default behaviour when `days` is omitted and does not describe output format, but the absence of an output schema and the small parameter surface make this acceptable.

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?

With a single `days` integer and 0% schema description coverage, the description must explain the parameter itself. It implies a lookback window through 'over the last days' and 'previous period,' but never explicitly says `days` controls the time range or that it is optional. This is partial compensation only.

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 states the tool's purpose as reporting on website performance over the last days and enumerates the metrics included (totals, top pages, sources, countries, devices, events). It clearly separates the 'people' and 'all_visits' views. While it lacks an explicit verb like 'get' or 'list', the title and content are unambiguous and distinguish it from all booking/owner siblings.

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 opens with 'Only for the Awning team,' establishing an access constraint, and ends with an explicit summarisation rule ('compare with the previous period and name the share of assistants'). However, it does not compare this tool to alternatives or state when not to use it, so the when-to-use guidance is largely implied.

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