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

With no annotations, the description carries the full burden and does disclose meaningful behavior: the API key materially changes scope, and plan tier caps the window (Free 7 days, Pro 30). It omits whether the operation is strictly read-only and how the key is actually supplied, which are the remaining gaps.

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?

Very compact and front-loaded: the output scope comes first, then the key/fleet behavior, then the tier limits. The telegraphic phrasing ('from what track_sessions has seen') is slightly awkward but every clause carries information.

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 two-parameter, no-output-schema, no-annotation tool, the description covers the output content, the data source, auth-driven scoping, and tier limits. The one actionable omission is how an API key is presented to the call, since no parameter exists for it.

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 both parameters are already documented, making 3 the baseline. The description adds a little meaning by tying fleet scoping to key presence and restating the tier-based day cap, but offers no syntax or format detail beyond the 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 specific output — which sandboxes were flagged idle and the idle time cost, broken down per provider — and ties the data source to track_sessions. It is clearly distinct from set_idle_rules (configuration) and weekly_report (time-based digest), though it doesn't explicitly contrast itself with those 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?

It gives real conditional guidance for the fleet parameter: omit it without an API key, and the call spans every fleet on that key. But there is no guidance on when to choose this over weekly_report or usage_and_upgrade, and no stated prerequisites beyond the key behavior.

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