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

The description discloses that subscribers flow into your contact list, which is an important side effect beyond the immediate creation. Annotations confirm readOnlyHint=false and destructiveHint=false, so the description aligns and adds value by clarifying the side effect. However, it does not mention other potential behaviors like whether it's idempotent, if landing pages have usage limits, or what happens on failure (e.g., duplicate name). With annotations already signaling a write operation, the description does enough to satisfy the bar.

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, efficient and front-loaded: the first sentence states the core action and resource, the second provides the key outcome and side effect. Every sentence adds unique value with 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?

There is no output schema, so the description compensates by noting the return of a public URL, which is adequate for a creation tool. However, it does not mention any required permissions, error scenarios (e.g., duplicate name), or behavior of related contacts. Given the moderate complexity (6 parameters) and good schema coverage, the description is sufficient but leaves some questions unanswered.

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 100%, so the schema itself documents all parameters thoroughly. The description only adds value by explaining the output ('Returns the public URL') and the side effect ('subscribers flow straight into your contact list'), but does not elaborate on any parameter meaning beyond what is in the schema. Baseline of 3 is appropriate as the description does not need to repeat schema info but also does not add depth.

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 action ('Create a hosted landing page with an email capture form' ) and a unique resource type ('hosted landing page'). It mentions a key outcome ('subscribers flow into your contact list'), which adds specificity. However, among siblings there are 'create_form' and 'create_campaign', and the description doesn't explicitly distinguish this landing page tool from those form or campaign creation 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?

No guidance is given about when to use this tool versus siblings like 'create_form' (for standalone forms) or 'create_campaign'. It does not state prerequisites (e.g., a verified domain) or when not to use it. The context is implied by the name and description, but explicit exclusions or alternatives are absent.

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