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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds meaningful behavior beyond that: default page size of 50, the nextCursor/cursor round-trip, and the fact that stopped sandboxes still appear unless includeStopped is set. It does not describe the response shape, but the pagination contract is the important disclosure here.

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 primary action and the most important constraint front-loaded. It is packed but nearly every clause carries information (filtering, pagination, stopped behavior, read-by-id). Slightly run-on, costing it a point.

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?

With no output schema, the description supplies the return-value contract an agent needs: paginated results with a nextCursor. It covers filtering, defaults, pagination, and the read-by-id mode, and the annotations cover safety. Nothing essential to correct invocation is missing.

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 only 43%, so the description must compensate, and it does: it clarifies includeStopped semantics, the 'key:value' label filter syntax, the cursor round-trip, page size, and that id switches to single-resource read. State, limit bounds and name format are left to the schema, which covers them, so the gap is minor.

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?

Starts with a specific verb+resource ('List your sandboxes') and scopes it precisely with the live/stopped distinction. It also notes the dual read mode ('Give id to read one'), which is useful but slightly muddles whether this is a list tool or a getter. It does not name the sibling that handles single-resource reads (runtime_sandboxes_inspect).

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 implied through the includeStopped toggle and the state/name/label filters, giving the agent context for when to use it. However, it never explicitly routes to alternatives like runtime_sandboxes_inspect for a single sandbox, nor does it state exclusions. Adequate but leaves the sibling selection to inference.

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