set_spend_limit

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It reveals that calling this tool resets the session window, so prior spending no longer counts, and that an agent key is required. This goes beyond basic semantics, though it could also mention idempotency or reversibility.

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 sentences, each earning its place: the main action, the critical reset behavior, and the prerequisite. No filler or redundancy. Front-loaded with the verb and resource, making the purpose immediately clear.

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 single-parameter setter with no output schema, the description covers the essential context: purpose, distinguishing from on-chain limits, auth requirement, and side effect (session window reset). It is sufficiently complete for an agent to select and invoke the tool, though it doesn't speculate on return values.

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 schema already provides 100% coverage for the single parameter, including units and an example. The description adds context by framing limit_raw as the session cap and noting the reset behavior, but it doesn't significantly alter or deepen the parameter's meaning beyond what the schema already states.

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's function: 'Set or update the agent's session spend cap'. The verb is specific, the resource is explicit, and it distinguishes itself from the on-chain creditLimit and sibling tools like get_spend_limit and clear_spend_limit by emphasizing the session window and operator-defined nature.

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 provides clear usage context: it is for operator-defined session caps, distinct from on-chain credit limits, and requires an agent key. While it doesn't explicitly name alternative tools or say 'when not to use', it gives enough directional guidance to differentiate from related limit-setting tools.

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