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

Annotations already declare readOnly, idempotent, openWorld, non-destructive, so safety is covered. The description adds context the annotations cannot: results come back ordered for driving with per-story durations and a total time, and the data set is confined to Washington roads — useful for setting expectations on a tool with no output schema.

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 sentences, front-loaded with the usage trigger, followed by concrete examples and then exclusions. No redundant or filler wording; every sentence carries decision-relevant information.

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 simple read-only lookup with two well-documented parameters and no output schema, the description covers trigger, input forms, exclusions, and return content. Only minor gaps remain, such as whether an empty stretch yields an empty list versus an error, and no explicit sibling routing.

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 100%, so the schema already documents both parameters including the direction enum. The description still adds value by showing the two accepted input shapes side by side (road+direction like 'I-90 west from Seattle', or a stretch id like 'sr520-03'), which confirms that an id alone is valid without a separate direction.

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?

Description names a specific verb+resource (return Sal's stories along a given highway stretch), states the scope (Washington only), and says what comes back (stories in driving order with durations and total time). The stretch-based framing implicitly separates it from the point-based sibling stories_near and the single-item sibling story.

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?

It gives an explicit trigger ('when someone asks what stories Sal has along a highway or stretch of road') plus examples and clear exclusions ('not for navigation, bookings, or roads outside Washington'). However, it never names alternatives such as stories_near or story for cases where the user gives a location rather than a stretch, so routing between siblings is left to inference.

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