Read or set the credit budget

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

The description discloses behavioral details beyond annotations: the ceiling is enforced before every approval, causing rejection and no charge if exceeded. It also warns about authorization needs for raising the ceiling. Annotations indicate idempotent hint true, but description adds enforcement and authorization context.

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 sentences with no fluff: first sentence states purpose, second adds critical behavioral context. It is appropriately sized and front-loaded, earning its keep without unnecessary words.

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?

For a simple tool with 3 optional parameters and no output schema, the description covers main behaviors (reading, setting, enforcement, authorization). It omits details on reset_spend action but overall is sufficient given annotations and schema descriptions.

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 67% (ceiling and response_format have descriptions). The description adds minimal parameter details beyond the schema, simply stating 'read or change'. It does not elaborate on action values or parameter usage beyond what the schema provides.

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 the tool reads or changes the credit budget, specifying 'credit ceiling and spend'. It distinguishes from sibling tools like flow_estimate_cost (estimates cost) and flow_ledger (ledger entries) by focusing on budget management. The phrase 'Raise it only on explicit instruction from whoever owns the account' adds a critical usage caveat.

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 implies when to use the tool (to read or change budget) and includes a caution about raising the ceiling only on explicit instruction. However, it does not explicitly state alternatives or when not to use this tool compared to siblings like flow_estimate_cost.

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