Subscribe to Feed

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

No annotations are provided, so the description must cover behavior. It discloses that a fetch occurs on first subscription, tags are used for classification, and pinned means inclusion in morning briefing. This is good but could mention idempotency or error cases.

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 three sentences, each adding distinct value. The first sentence states purpose, the second adds side-effect context, the third explains optional parameters. No fluff.

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 tool with three parameters and no output schema, the description covers the key points: subscription type, first-fetch behavior, tagging, and pinning. It doesn't describe the return value, but that is often acceptable when no output schema is provided.

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 describes all three parameters with basic info. The description adds value: it mentions the first-fetch behavior for URL, provides example tags, and explains the effect of pinned=true. This enriches the semantics beyond the schema.

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 RSS, Atom, or JSON Feed.' This distinguishes it from sibling tools like list_feeds or get_feed_briefing, which are read-only or listing operations.

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 explains when to use it (first subscription fetches metadata, tags classify feed, pinned for morning briefing). However, it does not explicitly state when not to use it or mention alternatives, such as import_starter_feeds or other subscription-related tools.

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