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

The annotation readOnlyHint=true already communicates that this tool is read-only, and the description's wording ('Inspect or summarize') is consistent with that. The description adds minimal extra behavioral context beyond the annotation, such as the fact that it deals with cost, but does not disclose other traits like response format, pagination, or any side effects. Since annotations cover the main safety aspect, the description is adequate but not enriched beyond the baseline.

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 a single, efficient sentence that immediately communicates the tool's core function. It is front-loaded with the action and resource, avoids redundancy, and contains no filler. Every word contributes to the meaning, making it exemplary in conciseness and structure.

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?

Despite a high schema coverage, the tool's dual modes ('recent' vs 'summary') are not explained in the description, leaving the agent unclear on what each action returns or how they differ. There is no output schema, so the description should compensate by indicating the nature of the response (e.g., whether it returns a list of calls or an aggregated cost summary). This gap means the description is not fully complete for an agent to correctly anticipate the tool's behavior without opening the schema or experimenting.

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 description coverage is high at 89%, meaning the individual parameter descriptions already convey their meaning. The tool description adds little beyond what the schema provides—it mentions 'recent' and 'USD cost' but does not elaborate on parameter specifics like how the 'action' enum ('recent' vs 'summary') affects the response. Since the schema does the heavy lifting, a baseline of 3 is appropriate; the description does not significantly enhance parameter understanding.

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 purpose: inspecting or summarizing recent Loadout action calls and their USD cost. The verb 'inspect' and 'summarize' clearly indicate the operation, and the resource (Loadout action calls) and the cost focus differentiate it from other broadly named siblings like 'auth' or 'billing'. It is unambiguous and distinct from the listed sibling tools.

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 this tool is used to audit or review Loadout usage and costs, but it does not explicitly state when to use it over alternatives or when not to use it. No sibling tools are mentioned as alternatives, and there are no exclusions or conditional guidance. The usage context is only implicit through the tool's name and purpose, so it meets the 'implied usage' level but lacks explicit direction.

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