la_metro_routes

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

Annotations already declare readOnlyHint=true, and the description's 'List' and 'Returns' align with a safe read operation. The description adds useful context about returned fields and bus/rail coverage, but it does not disclose behaviors like pagination, response size limits, or potential performance considerations.

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 two sentences, with the verb and resource stated first. Each sentence earns its place: the first announces the tool's action and scope, the second details the return fields and coverage. No unnecessary words or repetition.

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, no-parameter listing tool, the description fully explains what the tool does and what it returns. The readOnly annotation covers the safety profile, and the output fields are explicitly stated, making it complete for the tool's low complexity.

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 tool has zero parameters, so the baseline is 4. The schema coverage is trivially 100% and there is no parameter information needed. The description adds no parameter detail, which is appropriate since there are none.

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 lists all LA Metro transit routes, using a specific verb (List) and resource (LA Metro routes). It distinguishes itself from siblings like la_metro_vehicles or la_metro_stops by specifying route IDs, names, types, and colors for bus and rail lines.

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 (LA Metro routes) but no explicit guidance on when to use this tool over alternatives such as mbta_routes or la_metro_vehicles. It does not mention exclusions or name specific sibling tools, so usage is implied rather than explicitly directed.

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