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

Annotations mark this as non-read-only, non-destructive and non-idempotent, and the description adds context annotations cannot: the required sign-in sequence and the fact that the beta is free with no charge and no checkout link returned. It stops short of explaining what 'discontinue' actually does (reversible? immediate?), which for a state-changing action would be valuable.

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 sentences, no filler, with the auth prerequisite front-loaded ahead of the functional description. The cramming of four action values into a parenthetical keeps it dense but readable.

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 no output schema, the description usefully notes what is not returned (no checkout link), and auth is covered. But for a tool whose actions create, modify and terminate a plan, the absence of any detail on side effects, required permissions per action, or the role of 'tier' leaves meaningful gaps.

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 only 25%, so the description carries real weight here: it supplies the allowed values for 'action', which the schema leaves as an unconstrained string with no enum or description. However, 'tier' (needed for 'change') and 'service' are never explained, so the description only partially compensates for the coverage gap.

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 names a specific resource (a service's plan) and enumerates the concrete actions it supports (status | enroll | change | discontinue), which is far more specific than the title 'Manage a plan'. The opening verb 'See' is a slight mismatch with the mutating actions 'enroll/change/discontinue', but the action list resolves the ambiguity. It is clearly distinguishable from siblings like datailo_catalog or datailo_describe.

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 an explicit prerequisite flow, naming datailo_connect and datailo_connect_verify by tool name and noting the OAuth/key exception. It also scopes usage to plan management via the action list. It does not, however, say when to prefer this over other Datailo tools or what happens if a service has no plan.

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