Stops along a route

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

Annotations already declare readOnlyHint and openWorldHint. The description adds genuinely useful context beyond those: results are paged ('Long routes have 90+ stops, so results are paged') and coverage is geographically limited to Attica. It doesn't mention error behavior for an invalid route_code, which would earn a 5.

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, each carrying distinct information (scope, prerequisite, paging/coverage), with the core purpose front-loaded. Slightly dense in the middle but no filler.

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?

There is no output schema, so the description appropriately notes that coordinates are returned and that results are paged. Combined with the annotations, an agent has enough to call it correctly, though it doesn't cover what happens with an invalid or out-of-area route_code.

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 75%, so most parameters are partly documented structurally. The description adds meaning beyond the schema by explaining route_code's source ('from line_routes') and that pagination exists, explaining limit/offset's purpose. The 'language' parameter is left to its schema description, which is acceptable.

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?

States a specific resource and scope: 'ordered list of stops along one OASA route, with coordinates.' This clearly distinguishes it from siblings like find_stops (name lookup) and routes_at_stop (the inverse direction). The verb+resource+ordering are all explicit.

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?

Gives a prerequisite and provenance: 'Needs a route_code from line_routes — a line has several routes and each has its own stop sequence,' which tells the agent to obtain the code first and why a line isn't sufficient. It does not contrast with alternative stop-listing tools or state when-not to use it, so it stops short of a 5.

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