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

Annotations already indicate this is not read-only, but the description adds concrete behavior beyond them: it returns a TR-YYYY-NNNN identifier and counts against a 20-trip monthly quota based on trip date. No annotation contradiction is present.

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 short sentences front-load the core action and fields, followed by return value and quota constraint. No filler or repetition of schema 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 9-parameter create tool with a detailed schema, the description covers the essential return value and quota behavior. Optional parameters like note and jurisdiction are left to the schema, which is acceptable; it could only add marginal clarity about what happens when the free tier is exceeded.

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 coverage is high (89%), so the schema carries parameter documentation. The description names the main captured fields and the allowed categories, but adds little beyond the schema's own descriptions.

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 opens with a specific verb and resource — "Log one drive in the mileage log" — and enumerates exactly which fields are captured (date, from/to, distance, purpose, category). This clearly separates it from sibling list/remove/export/rate 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 intended use is explicit: record a new trip when the user supplies trip details. It doesn't explicitly name sibling alternatives or exclusions, but as the only create-style trip tool among read/delete/export siblings, the context is clear; the free-tier note adds a practical condition.

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