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

Annotations already cover readOnly, idempotent, non-destructive and closed-world behavior, so the bar is lower; the description still adds the auth scope requirement and the returned fields (name, email, role). It does not describe behavior when the ID is unknown, which is the only notable gap.

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?

Three short sentences, each carrying distinct payload (identity of the lookup key, return contents, permission requirement), with the verb+resource front-loaded and no filler.

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 single-parameter read tool with no output schema, the description is nearly complete: it names the scope requirement and the returned fields, so an agent knows what it gets back. Error/not-found behavior is unstated, which is a minor omission.

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?

One string parameter at 100% schema coverage, with the schema already documenting it as a Clerk user ID. The description's phrase 'by their user ID' adds no format or syntax detail beyond the schema, so the baseline 3 applies.

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?

States a specific verb and resource ('Get a specific organization member by their user ID') and implies single-record retrieval as opposed to the sibling list_users. It does not explicitly name an alternative tool, so differentiation is by inference rather than declaration, keeping it just below a 5.

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 supplies a prerequisite ('Requires users:read scope'), which is real guidance, but says nothing about when to use this versus list_users or how to obtain a user ID. Usage is implied by 'specific ... by their user ID' only.

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