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

Annotations declare the mutation profile, and the description adds context beyond them: the confirmed-owner-email prerequisite, the plan/quota failure mode, the required scope (locations:write, Admin role), and the exact return shape. This is a mutation tool and the description covers consequences and prerequisites thoroughly.

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?

Purpose is front-loaded and every sentence carries load (roles, prerequisite, quota, exclusions, return, scope). Dense but slightly cluttered by embedded plan and scope details that could be ordered more cleanly.

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 two-parameter mutation tool with no output schema, the description covers purpose, roles, prerequisites, quota behavior, sibling exclusions, return values, and required auth scope. Nothing an agent needs to call it correctly 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 coverage is 100%, but the schema's role parameter description explicitly defers role meaning to the description, and the description defines ADMIN, SCHEDULER, and DOCK_STAFF capabilities. The email parameter is left to the schema, so it exceeds the baseline without fully documenting every parameter.

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 a specific verb and resource ('Email someone an invitation to join the organization'), which is immediately distinguishable from every sibling tool in the list. No restating of the title or tautology.

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 away for the adjacent operations: 'Listing, changing, and removing members happen in Settings → Members, not over MCP.' It also states the precondition (owner's email must be confirmed) and the plan-limit consequence (payment_required past the Free tier).

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