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

With no annotations, the description discloses that it is a read-only check (returns balance), that it affects patron top-up certification, and that it is free. It does not mention rate limits or error behavior, but for a simple read operation, this provides adequate transparency.

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 description is four concise sentences, front-loaded with the primary purpose, followed by consequences and a clarification. Every sentence adds value without 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?

Given the tool has no parameters and an output schema, the description explains the return value (sats), the business logic (balance affecting certification), and the follow-up action (purchase_credits). No gaps are apparent.

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 no parameters, so the schema coverage is 100% vacuously. Baseline for 0 parameters is 4, and no additional parameter details are needed.

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 clearly states it checks the operator's tax balance at the Authority, specifically the sats available for certifying patron credit purchases. It distinguishes from sibling tools like schwab_check_balance (patron balance) and schwab_check_oauth_status by specifying it's the operator's own funding.

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 description explains when to check this balance (when certifying purchases) and what to do when it reaches zero (call purchase_credits). However, it does not explicitly compare to alternatives like schwab_check_balance for patron balances, leaving some ambiguity.

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