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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is covered. The description adds useful context on what each insight_type yields (per-weekday averages, per-day totals) and the endpoint path, but says nothing about permissions, rate limits, or response shape.

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?

A single dense sentence that front-loads the returned data types and ends with the route template; no filler sentences, and the per-parameter qualifiers are kept inline in parentheses.

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 5-param, no-output-schema read tool, the description covers the primary discriminator (insight_type) and its variants. Minor gaps remain: it doesn't clarify that timeout and writes_only act as global filters across insight types.

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 80%, so most parameters are self-documenting. The description goes beyond the schema by explaining the semantics of the otherwise undescribed insight_type enum values (days = per-day totals with optional weekday, weekdays = average per weekday), which is the key parameter for steering the call.

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 gives a specific verb+resource ('One WakaTime insight for a range') and enumerates the supported insight types, so an agent knows exactly what the tool returns. It stops short of differentiating itself from siblings like wakatime_get_stats or wakatime_get_summaries, leaving the overlap ambiguous.

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 insight_type enumeration and the 'weekday is only for days' note; there is no explicit statement of when to choose this tool over get_stats, get_summaries, or get_durations. Adequate but no when/when-not guidance.

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