mbta_alerts

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

The annotation readOnlyHint=true already conveys that this is a safe read operation. The description adds useful scope (what kinds of alerts are returned) but does not disclose additional behavioral traits such as pagination, default limits, or how 'active' is determined. With the annotation covering safety, a 3 is appropriate.

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, front-loaded with the core purpose, and includes the essential details (alert types, optional filter) with no filler. Every word earns its place.

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?

This is a simple read-only tool with two optional parameters, both well-documented in the schema, and no output schema is required. The description explains what the tool returns and the filtering option, which is complete for an agent to select and invoke it correctly. The annotation covers safety.

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 100%, so the schema already documents both 'limit' and 'route' with examples and defaults. The description only paraphrases the route filter ('Optionally filter by route') and adds no new semantic information beyond what the schema provides. Baseline 3 applies.

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 uses a specific verb ('Get') and identifies the resource ('service alerts for MBTA (Boston) transit'), and it lists the types of alerts (delays, suspensions, detours, planned changes) and the optional route filter. This clearly distinguishes it from sibling tools like mbta_predictions, mbta_vehicles, and mbta_routes.

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 clearly states that this tool provides MBTA service alerts and optionally filters by route, which gives sufficient context for when to use it (when the need is for MBTA alerts). However, it does not explicitly mention alternatives or exclusions (e.g., 'for predictions, use mbta_predictions'), 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.