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

Beyond the annotations (readOnlyHint, idempotentHint), the description adds concrete behavioral details: no auth, no state changes, no charges, and specifically that it returns first-party URLs without creating Stripe sessions or granting credits. This significantly clarifies side effects and auth requirements, exceeding what the annotations alone convey.

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 two sentences, front-loads the primary purpose in the first sentence, and uses the second for essential behavioral constraints. Every clause adds value with no redundancy or 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?

With an output schema present, return values are documented elsewhere. The description covers the critical context: it's a public read-only listing, no auth or side effects, and the exact behavior regarding URLs and Stripe sessions. Given the simple optional parameters and existing annotations, this is fully 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?

The input schema has 100% coverage with descriptions for all three parameters (kind, interval, include_checkout_links). The description does not add parameter-specific semantics beyond what the schema provides, so the baseline of 3 is appropriate.

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 public Cannon Studio plans, credit packs, and team offerings.' This clearly identifies the tool's function and categorizes what it returns, distinguishing it from sibling tools like list_capabilities and list_toolkits by focusing on offerings.

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 provides clear usage context: 'Public read-only: no auth, no state changes, no charges' tells the agent this is safe to call without credentials or side effects. The phrase 'without creating Stripe sessions or granting credits' implies when not to use it, contrasting with tools like get_checkout_link, though it doesn't explicitly name an alternative.

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