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

Annotations already cover read-only, idempotent, and non-destructive hints. The description adds genuinely new behavioral context: the required auth scope, the full enumerated set of possible statuses, that tree ids are only present once fulfilled, and the recommended polling cadence. This goes well beyond the annotations and does not contradict them.

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?

Three short sentences, each earning its place: safety/auth, return content, and polling guidance. The most critical fact ('Read-only') is front-loaded, and there is no redundancy with the schema or annotations.

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?

Despite having no output schema, the description explains what the caller gets back (status enum plus tree ids when fulfilled). It also covers the auth precondition and the polling behavior needed for the post-payment flow. For a single-parameter, low-complexity tool, nothing essential 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 100%, with the order_id parameter already documenting its format, pattern, and source ('from start_sponsorship'). The description adds no additional parameter semantics, which is fine because the schema carries the full burden. Baseline 3 applies.

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 clear verb-resource pair ('status of one of the user's orders') and specifies the exact return content. It distinguishes itself from a list tool like my_orders by emphasizing 'one of the user's orders', though it does not explicitly name the sibling alternative.

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?

Provides concrete usage context: the required OAuth scopes and a polling interval ('Poll every 10 seconds or more after the user pays'). It does not explicitly state when to prefer a sibling like my_orders, but the single-order scope and post-payment polling guidance give sufficient situational direction.

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