user_permissions_create

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

No annotations are provided, so the description carries full burden. It indicates a write operation and requires confirm=true, but does not explain whether permissions are appended or overwritten, or what happens to existing user permissions. More detail on behavioral impact would improve transparency.

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?

The description is a single sentence that efficiently conveys core information. It is front-loaded with '[WRITE]' for immediate recognition, and every word serves a purpose.

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 5 parameters and no output schema, the description is adequate but incomplete. It covers the basic purpose and a key requirement, but does not explain the interplay between account-level and container-level permissions, nor specify the response format. More detail would help an agent understand the full scope of the operation.

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 baseline is 3. The description does not add parameter-specific meaning beyond what the schema provides. It references confirm as a prerequisite but doesn't elaborate on accountPermission or containerAccess semantics.

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 clearly states the verb 'Grant' and the resource 'user access to a GTM account (and optionally containers)', immediately distinguishing it from sibling tools like user_permissions_get/update/delete. The prefix '[WRITE]' further clarifies the action type.

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 specifies prerequisites (GTM_MCP_ENABLE_WRITES=true and confirm=true), providing clear context for when to use this tool. However, it does not explicitly exclude use cases or mention alternatives among sibling tools.

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