Router savings summary

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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world, so the safety profile is covered. The description adds the useful cost fact ("Free") and states the report's contents. It does not disclose the default lookback window when 'days' is omitted, which is meaningful behavior for a summary tool.

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 short sentences, front-loaded with the report's content, and the trailing "Free." carries real decision value at minimal cost. Nothing is redundant.

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?

With no output schema, the description does carry the burden of explaining returns, and it sketches them (wins per market, savings vs baseline pricing) without detail on shape. The missing default time window and lack of sibling differentiation leave it only minimally adequate for a free analytical report.

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 0% for the single 'days' parameter, and the description says nothing about it — no default value, no note that 1–90 is the permitted range, and no indication of what window is used when it is omitted. With only one parameter the description could easily have compensated, so the gap is a real one.

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 names the specific resource and content: how /router requests were served, wins per market, and savings versus Carpe-only pricing. That is far more specific than the title alone. It does not distinguish itself from close siblings like carpe_usage_summary or carpe_pricing, so an agent must infer the boundary.

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?

There is no explicit when-to-use guidance and no named alternative among the many usage/pricing siblings. The word "Free" hints that it is a zero-cost call, which is mild encouragement, but the agent is left to infer when this report is preferable to carpe_usage_summary or carpe_session_spend.

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