Route Shape

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

With no annotations, the description carries the behavioral burden and does well: it explains output formats, Douglas-Peucker simplification, pattern ranking, and span slicing semantics including first-visit behavior for repeated stops. It does not explicitly state read-only behavior or permission requirements, leaving a minor gap.

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 dense but front-loaded around the core return value and then adds important optional behavior. The single long sentence is efficient, though the packed clause structure could be slightly harder to scan.

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?

An output schema exists, so return-value structure does not need full explanation. Still, for a complex 7-parameter tool with no annotations and 0% schema coverage, the description leaves required-parameter meaning and usage routing insufficiently covered.

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%, so the description must compensate, and it does for most parameters: format, pattern rank, simplify_m, and from_stop/to_stop semantics are explained. However, it does not clarify the required route identifier format or what direction values '0' and '1' mean, leaving key required-parameter semantics implicit.

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 precisely what the tool returns: a route direction's most-used stop pattern geometry as polyline or GeoJSON, with stops and distance along the shape. It distinguishes itself from siblings like route_stops by describing the geometric shape plus stop distances rather than just an ordered list of stops.

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?

Usage is implied by the geometry-focused description, but there is no explicit when-to-use or when-not-to-use guidance relative to siblings such as route_stops or stop. The agent can infer context but must decide on its own when this tool is preferable.

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