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

Annotations already cover the safety profile (readOnlyHint=true, openWorldHint=false), and the description adds useful behavioral detail beyond them: the result set includes both running AND paused sandboxes, and it names the returned attributes (mode, tariff, state, expiry). The 'Requires: token' note flags the auth dependency that the empty parameter schema leaves unexplained.

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?

Two short clauses, front-loaded with the action and scope, with the auth requirement appended. No filler, though 'Requires: token' is terse enough to be slightly ambiguous about where the token is sourced given no token parameter exists.

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 usefully enumerates the returned fields and the included states, and annotations carry the read-only safety profile. A minor gap remains around pagination/ordering, but nothing essential for 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?

There are zero input parameters, so the baseline is 4. The description appropriately adds no parameter detail and instead documents the shape of what comes back, which is the more relevant information for a no-arg tool.

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?

States a specific verb ('List') and resource ('the account's sandboxes') and narrows scope to running and paused instances. It clearly contrasts with the singular sibling get_sandbox by implication, though it never names that sibling 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?

Usage is implicitly clear (query the account's sandbox inventory), and it discloses the auth prerequisite 'Requires: token'. However, it gives no explicit when-to-use-vs-alternatives guidance, e.g. when to reach for get_sandbox, sandbox_pricing, or create_sandbox instead.

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