substack_publication

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

With no annotations, the description carries the behavioral burden. It discloses meaningful traits beyond the purpose: exactly one identifier is required, and resolving by name is more expensive because it parses the full homepage, while publication_id reads a compact document. It does not discuss auth, rate limits, or error cases, but the read-only nature and key cost behavior are transparent.

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?

Four sentences with no filler: purpose and return contents are front-loaded, then identifier guidance is kept together and explained concisely. The output detail is long but earns its place because there is no output schema.

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?

Given there is no output schema, the description compensates by spelling out what the response contains and how to choose the identifier. It is missing explicit error/auth behavior, but for a public profile-and-plans lookup the practical calling context is fully covered.

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%, so the baseline is 3, and the description adds real value on top: concrete name examples (semianalysis, www.thefp.com), the exact-one-of-two constraint, and a cost-based reason to prefer publication_id. The schema leaves required empty, so this clarification is especially useful.

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 uses a specific verb and resource ('Get a Substack publication and its subscription offering') and enumerates the exact returned data: web plans, per-currency pricing, App Store plans, benefit copy, and sale toggles. This clearly separates it from sibling tools like substack_publication_posts or substack_publication_contributors.

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?

It gives clear context for when to call: when a publication's profile and full subscription offering are needed. It also specifies identifier usage ('exactly one is required') and recommends publication_id for efficiency, but it does not explicitly name alternatives among the many substack_* siblings or state when not to use this tool.

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