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

Annotations already declare destructiveHint=true, idempotentHint=false and openWorldHint=true, so the mutation risk profile is covered structurally. The description adds genuinely new context: the invite is only dispatched after the user approves a link the agent must show them, and prioritised-account changes draw down a monthly quota. It does not say what state is lost on unpinning or whether subscription assignment is reversible, so beyond the approval flow the disclosure stays thin.

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?

One long sentence enumerates the actions with their parameters, followed by a short sentence on quota cost and one on the prerequisite read. Front-loaded and mostly waste-free, though the parenthetical parameter lists make the first sentence dense enough to be re-read.

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?

A three-action multiplexed mutation tool with rich annotations and an output schema; the description covers all three actions, their required inputs, the read-first prerequisite and the quota consequence. What is missing is per-action confirmation semantics (e.g. whether set_prioritised_accounts is recoverable once accounts are unpinned).

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 baseline is 3, but the description adds cross-parameter meaning the schema states only per-field: which parameter pairs belong to which action (email + role, license_id + user_ids, ds_id + account_ids) and that IDs come from get_user_and_team. That conditional mapping is real value beyond the field-level descriptions.

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?

Names the specific resource (Supermetrics team) and enumerates the three concrete operations with their verbs: invite a member, assign users to a subscription, replace a data source's prioritised accounts. Each action is tagged with its enum value, so an agent can map intent to action without opening the schema.

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?

Explicitly routes the agent to get_user_and_team first to obtain license_id, member user_ids and existing pins, and states the approval-link prerequisite for invites. It does not state any when-not-to-use case or warn about combining multiple actions in one call, which keeps it short of a 5.

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