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

Annotations already declare readOnly, idempotent, and non-destructive, so safety is covered. The description usefully adds the 1-90 day bound and notes that outgoing calls report person-reach rates, but stays silent on what happens when no assistant is specified (all assistants vs. error) and on result size/pagination, which matters for a report tool.

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 with the [read] tag and scoping qualifier front-loaded, followed by the payload list. Every clause carries information; the awkward parenthetical and slash-heavy phrasing cost it a point but nothing is wasted.

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?

There is no output schema, so the description's list of report contents does useful duty describing the return. Still, for a four-parameter tool with zero schema coverage, the undocumented direction filter and the unstated behavior when no assistant is provided leave an agent guessing on two real decision points.

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 0%, so the description carries the burden; it does explain `days` (1-90) and the id/uuid pair's purpose, adding real meaning. However `voip_call_direction` is never mentioned anywhere, leaving one of four parameters undocumented, and defaults (30 days, null) are not restated.

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 the resource (VOIP assistant activity report) and enumerates the contents: calls, minutes, dispositions, topics, per-day and per-hour breakdowns. That is specific enough to separate it from list_voip_calls or get_voip_call, though it never names those siblings explicitly.

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 parenthetical implies you scope the report to one assistant via id or uuid, and the `days` window (1-90) is stated, so usage is inferable. But it never says whether the assistant identifier is mandatory (all params are optional in the schema), nor when to prefer this over list_voip_calls or get_voip_call — no exclusions are given.

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