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

readOnlyHint=true already tells the agent this is a safe read. The description adds useful context beyond the annotation by identifying the underlying endpoint and confirming cursor-style pagination, but it discloses nothing about rate limits, auth scopes, or result volume behavior.

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?

Two short sentences that are front-loaded with the resource and then the capabilities. No filler, no repetition of the title, and the endpoint mapping is compact.

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 zero-required-param read tool with a fully documented schema, a readOnly annotation, and no output schema, the description covers the essentials including the pagination model. It could be stronger by noting how next_page_token is consumed, but nothing critical for invoking it is missing.

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 already documents filter syntax, order_by, page_size cap, and page_token origin. The description adds only a generic mention of filtering/ordering/pagination, so the baseline 3 applies.

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 and resource pair ('List recurring subscriptions / payment plans') and pins it to the Keap GET /subscriptions endpoint. It is clearly distinguishable from resource siblings like keap_list_orders or keap_list_contacts, though it does not explicitly name a sibling it must not be confused with.

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 names supported capabilities (filtering, ordering, cursor pagination) but never states when to use this tool versus alternatives or any prerequisites. Usage is only implied by the resource name, which is the minimum viable level.

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