spend_status

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

No annotations are provided, so the description carries the burden. It clearly frames this as a reporting/status read, which is the main behavioral fact, but it says nothing about auth requirements, whether the period is configurable, or freshness of the data. For a zero-parameter read tool the risk surface is small, so this is adequate rather than strong.

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?

A single tight sentence with the core value front-loaded ('what you've spent this period') and the qualifiers (by model, against budget and caps) trailing efficiently. Nothing is wasted.

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?

An output schema exists, so return values need not be explained, and the description correctly focuses on what the tool reports. It is nearly complete; only a note on the meaning of 'this period' or read-only status would close the remaining gap.

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 tool takes zero parameters, so the baseline of 4 applies. There is no parameter behavior the description needs to compensate for.

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?

States a specific resource and scope: current-period spend, broken down by model, measured against budget and caps. That distinguishes it implicitly from estimate_cost (forward-looking) and preapprove_spend (approval), though it never names those siblings directly.

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?

Usage is implied by the content ('what you've spent this period'), but there is no explicit when-to-use statement or routing against the spend-related siblings estimate_cost and preapprove_spend. An agent can infer the context but must do the disambiguation itself.

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