substack_user_connections

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

With no annotations, the description carries the full burden and discloses meaningful behavior: the lists are public, each entry is a full profile in the same shape as /substack/user with subscriber signals, and the upstream returns only a bounded preview. Pagination, sorting, and error cases are not covered, but key read-only behavior and output shape are clearly stated.

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?

Every sentence earns its place: the first states the action, the second defines the return shape, the third resolves how to obtain user_id, and the fourth warns about the bounded preview. It is front-loaded and contains no filler.

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 simple two-parameter tool with no output schema, the description is adequately complete: it provides the entry shape, the id source, and the preview limitation. It would be stronger with details about pagination or empty-list behavior, but an agent has enough to call it correctly.

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 coverage is 100%, with both user_id and list already described in the input schema. The description mostly restates the user_id provenance ('numeric id returned by /substack/user') without adding new parameter-level detail. Thus it stays at the baseline for high schema coverage.

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 opens with a specific verb and resource: 'List a Substack user's followers, following, or subscribers,' and clarifies it returns 'public connection lists.' This is unambiguous about what the tool does, though it does not explicitly name or contrast a sibling tool such as substack_user_activity.

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 gives practical guidance by pointing to /substack/user as the source of user_id and by noting the list parameter selects among followers, following, or subscribers. It also flags the bounded-preview limitation, which helps an agent decide if this tool is sufficient. It stops short of explicit when-not-to-use or alternative-tool routing.

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