spend_reward_points

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

It reveals a non-obvious, live-verified API behavior: the endpoint returns 500 if the balance would go negative. This goes well beyond the annotations, which only list generic hints, and it gives the agent a concrete way to avoid failure.

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 focused sentences: the first names the operation, the second delivers a verified caveat and mitigation. No filler or redundant restatement of the schema.

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?

Given a simple 2-parameter schema, full schema descriptions, and an output schema, the description covers the main action and the critical precondition. It is slightly incomplete only in that it does not clarify what 'a reward' refers to or whether any reward state must exist before spending.

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 coverage is 100%, so the schema already documents both parameters (points and date) adequately. The description does not add parameter-level detail beyond the schema; the balance warning relates to the overall operation, not a specific parameter's format.

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 uses a specific verb and resource — 'spend reward points on a reward' — so it clearly states what the tool does. It does not explicitly compare against sibling tools like claim_reward_points or reset_reward_points, so it falls just short of full differentiation.

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 note gives actionable guidance: check the balance (get_account_info) before large purchases to avoid a 500 error. It does not explicitly say when not to use this tool or name an alternative, but it provides clear situational context.

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