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

With no annotations, the description carries the burden. It discloses the return value ('Returns the created membership'), cost ('Cost = 10 tokens'), and prerequisite behavior (get_connected_accounts, default connection). Missing permission requirements and idempotency, but covers key operational context.

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?

Four concise sentences, front-loaded with purpose, followed by prerequisite, return, and cost. Every sentence earns its place; 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?

Given full input schema and an output schema, the description adds vital cross-tool dependency and default-instance behavior. It's sufficient for smooth invocation, though edge cases like existing memberships or admin permissions are not addressed.

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. The description's note about clerk_instance_id primarily restates the schema's 'Omit to use the default connected account,' adding no new parameter-level meaning beyond reinforcing the prerequisite call.

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?

Opens with 'Add a user to a Clerk organization with a specified role' – a clear verb, resource, and scope. This distinguishes it from sibling tools like delete_organization_membership, update_organization_membership, and list_organization_memberships.

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 instructs to call clerk.get_connected_accounts first and explains how to handle clerk_instance_id (target specific connection vs. default). However, it doesn't explicitly mention when to prefer this over alternatives like create_organization_invitations.

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