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

Annotations already declare readOnlyHint=true and destructiveHint=false, but the description reinforces this by explicitly disclaiming side effects ('Does not submit a refund or cancel anything') and stating the agent's capability boundary. It does not address the idempotentHint=false flag or any auth/rate-limit behavior, so it is strong but not exhaustive.

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, front-loaded with the read action and scoping, followed by the negative capability and side-effect disclaimers. No filler or redundancy.

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?

An output schema exists, so return values need no explanation. For a single-parameter read tool, the description covers purpose, ownership, and the critical boundary that agents cannot initiate refunds, leaving nothing an agent needs to call it correctly.

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?

The single request_id parameter is fully documented in the schema (100% coverage), including where the refund originates. The description repeats that origin context but adds no new format, validation, or lookup semantics 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?

States a specific verb and resource ('Read the progress of a refund') plus precise scope ('the account owner requested at nomac.app/usage'). It is clearly distinguishable from billing siblings like get_billing_status or get_checkout_link without opening either schema.

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?

Explicitly scopes who this is for and what it is not for: agents cannot request refunds and should redirect the human to nomac.app/usage. It gives clear context but never names a sibling alternative by name for related needs (e.g. where to check billing state instead).

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