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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint, and destructiveHint, so the safety profile is fully covered by structured data. The description adds a useful enumeration of what each alert contains, but discloses nothing extra about rate limits, caching, freshness, or how up-to-the-minute the data is.

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?

Two tight sentences: the content/resource is front-loaded, followed by the authoritative-use clause. Every clause earns its place with 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?

With no output schema, the description carries the burden of explaining return content, and it does so competently by listing cause, effect, affected routes/stops, and the active period. Minor gaps remain on data freshness and result ordering/size, but an agent has enough to call it correctly.

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 both the optional route filter and _apiKey are already documented in the schema with an example. The description adds no additional parameter meaning beyond what the schema provides, so the baseline of 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?

States a specific verb and resource (current TriMet service alerts) and enumerates the payload categories (detours, disruptions, elevator/stop closures, cause, effect, affected routes/stops, active period). It is clearly distinguishable from the trimet_arrivals, trimet_stops_near, and trimet_vehicles siblings.

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 'AUTHORITATIVE for "is anything disrupted on TriMet right now"' line gives a concrete decision trigger for reaching for this tool. However, it names no alternative tool or exclusion (e.g. when to prefer recent_alerts or a sibling), so the routing guidance is clear but not exhaustive.

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