route_messages

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

Annotations already declare destructiveHint=true/readOnlyHint=false, but the description explains the mechanism behind that: each message is returned once and repeated calls yield only newly arrived messages. This is exactly the behavioral context annotations cannot convey, and it matches the annotations rather than contradicting them.

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, zero filler, and the ordering plus capture precondition are front-loaded before the destructive-read caveat. Every sentence carries distinct information.

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 still discloses return ordering ('newest last') and the once-only return semantics, which is what an agent most needs here. Safety profile is covered by annotations and reinforced coherently by the text.

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?

One parameter with 100% schema description coverage ('The route name.'), so the schema already carries the meaning. The description adds no syntax or format detail for the name parameter; baseline 3 is appropriate.

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 ('Return the most recent messages captured on a route') plus ordering ('newest last'), and the capture_last constraint scopes it away from status/list style siblings. An agent can tell what it fetches without opening the schema.

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?

Explains the precondition for any result ('Only routes started with capture_last capture anything') and warns that reads are one-shot, which strongly shapes when to call it. It does not name alternative tools (e.g. list_routes, route_status), so it stops short of explicit alternatives.

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