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

The description discloses key behavioral traits: fallback to activity if traffic feed is unusable, weighting by event severity, and inclusion of reason in output. Annotations mark it as readOnly and openWorld, but the description adds valuable context beyond those hints.

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 structured into clear paragraphs: purpose, ranking criteria, fallback, and output format. It is slightly verbose but every sentence adds value. The main purpose is front-loaded.

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?

The description covers the tool's purpose, ranking logic, fallback behavior, and output format (counts and reason). Without an output schema, this provides sufficient context for an agent to understand what to expect.

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 description explains the 'by' parameter's values ('activity' vs 'congestion') and their meanings. The 'limit' parameter is not explicitly described, but its default and role are implied by the output description. Given 0% schema coverage, the description compensates well but could be more explicit about 'limit'.

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 clearly states the tool ranks major corridors by activity or congestion, answering broad traffic questions. It distinguishes itself from sibling tools like check_route or get_incidents by providing an aggregated overview across all 17 tracked corridors.

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 on when to use the tool (for broad questions like busiest routes) and implies not for specific details (handled by siblings). However, it does not explicitly state when not to use it or name alternative tools.

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