subscribe

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

No annotations are provided, so the description carries the full burden. It states a basic mutation ('Subscribe') and the effect ('Add a route to your subscription list'), but it does not disclose potential side effects (e.g., whether an existing route is overwritten), authentication requirements, error behavior, or idempotency. This is a significant gap for a state-changing tool.

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 short sentences that each add value: the first defines the operation, the second gives context. No redundant phrases or filler, and the key information is front-loaded.

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?

The description adequately conveys the purpose and outcome of subscribing, but lacks information about return values, error handling, or behavior on duplicate subscriptions. Since there is no output schema and no annotations, a bit more detail would be expected for full completeness, though the tool is relatively simple.

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%, with clear descriptions for 'route', 'name', and 'params'. The tool description itself adds no parameter-specific meaning beyond what the schema already provides, so the baseline score of 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?

The description clearly states the action ('Subscribe to an RSSHub feed') and the concrete outcome ('Add a route to your subscription list'). It distinguishes the tool from siblings like get_feed and search_routes by focusing on the persistent subscription action.

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 phrase 'for easy access later' implies a use case: saving a route for future retrieval rather than immediate fetch. However, it does not explicitly contrast with alternatives such as get_feed or list_subscriptions, so it lacks full when/when-not guidance.

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