spending_report

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

No annotations are provided, so the description carries full burden. It explicitly states 'Free — no payment is made,' revealing that invoking the tool has no financial side effects. It also uses 'Show' which implies a read-only operation, providing transparency about its non-destructive nature.

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 two short sentences, front-loaded with the core function and ending with a helpful cost note. Every word earns its place, with no filler or redundant details.

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 read-only report tool with no parameters, no annotations, and no output schema, the description fully covers what the agent needs to know: what it shows (caps, spent amount, payments), scope (this session), and cost (free). It leaves no significant gaps.

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 input schema has zero parameters, so there is nothing for the description to explain. As per the baseline for 0 params, a score of 4 is appropriate. The description nonetheless clarifies that the report is about the current session, adding context beyond the empty 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?

The description states a specific verb ('Show') and resource ('this agent's spending caps, how much it has spent so far, and every payment it has made in this session'). It clearly distinguishes itself from siblings by focusing on reporting spending data rather than performing actions.

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 context for when to use the tool (to check spending caps, total spent, and payments in the session). It does not explicitly name alternatives or exclusions, but states 'Free — no payment is made,' which signals it is a safe, non-costly action. This is clear enough, though not fully explicit about when not to use it.

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