upsert_subscriptions

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

With no annotations, the description carries the full burden. It discloses the write behavior (create/update), the return value (canonical feedUrls), and a storage transformation rule (known RSSHub URLs stored as rsshub://...). It stops short of explaining failure modes or idempotency, but the core behavioral traits are present.

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 sentences with no filler. The primary purpose is front-loaded, and the return/storage detail follows immediately in the second sentence.

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 one-parameter upsert tool, the description covers the essential operation and return, but the lack of parameter semantics and any guidance relative to siblings leaves meaningful gaps. It is minimally complete but not fully self-sufficient.

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 0%, and the description does not elaborate on the 'items' array structure or the title/category fields beyond mentioning feedUrls. It adds operational meaning ('upsert' and canonicalization) but leaves required-field semantics and array constraints to the schema alone.

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 states a specific verb and resource: 'Create or update RSS subscriptions'. It also adds a distinguishing detail, the return of canonical feedUrls and the rsshub:// storage convention, which sets it apart from the sibling list/remove tools.

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 intended usage is implied by 'Create or update RSS subscriptions' — use this when adding or modifying subscriptions. However, it does not explicitly mention when to prefer this over siblings like list_subscriptions or remove_subscriptions, nor does it provide exclusions.

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