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

Annotations already declare readOnlyHint=true, openWorldHint=false and destructiveHint=false, so the safety profile is covered structurally. The description adds which fields are read and a recovery precondition, but the 'resume a blocked build once with a new request_key' instruction is ambiguous on a read-only tool and is not clearly scoped to this tool rather than the build sibling.

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?

The returned-data list is front-loaded and compact, which is good. However, the trailing workflow sentences (resume the build, reconcile outcomes) are dense and read as belonging to the build tool rather than a status read, which muddies the structure.

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 an output schema present, return values need not be explained, and with zero parameters there is no input contract to document. The description supplies the field inventory and a workflow precondition, leaving it largely complete for a zero-param read tool.

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 and the schema cannot be under-served. The mention of a 'new request_key' is not a parameter here and could briefly confuse the agent, but no parameter semantics are actually missing.

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 opening clause names a specific read verb and enumerates the resource fields it returns (payment, contracted price, quota/reset, renewal, guarantee), so the agent knows this is a billing/plan status read. It does not, however, distinguish itself from billing-adjacent siblings like get_checkout_link or get_refund_status, and the title ('Get build plan status') drifts from the name ('get_billing_status').

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 second sentence gives a conditional workflow ('resume a blocked build once ... only if the earlier response said build_started:false') and a precondition ('reconcile unknown build outcomes first'), which implies context. But it never tells the agent when to call this tool versus the checkout/refund/build siblings, and the guidance is tangled.

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