feedbin_create_subscription

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

With no annotations, the description carries the behavioral burden and does disclose that the operation mutates Feedbin state and may return multiple feed choices—useful context beyond structured fields. However, it omits auth requirements, duplicate-subscription behavior, and idempotency, leaving meaningful gaps for a mutation 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?

Three short sentences, front-loaded with the action, and each clause contributes a distinct fact (purpose, mutation, return quirk). Nothing is wasted.

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 mutation tool with no annotations and no output schema, the description covers purpose, side effect, and a return-value quirk. It still leaves open how to handle multiple feed choices and duplicate subscriptions, so it is minimally adequate rather than complete.

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% for the single required feed_url parameter, and the description only repeats the parameter name while implying it is a URL. It does not explain accepted formats, whether feed IDs are accepted, or any validation constraints.

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 (subscribe) and resource (feed_url / feed subscription), and 'Mutates Feedbin state' disambiguates it from read-only siblings like feedbin_list_subscriptions. It does not explicitly contrast with feedbin_update_subscription or feedbin_delete_subscription, but the action is clear enough to distinguish it.

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?

There is no guidance on when to use this versus updating an existing subscription (feedbin_update_subscription) or listing subscriptions; the agent must infer usage from the verb alone. No exclusions or alternatives are named.

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