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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, covering the safety profile. The description adds useful behavioral context beyond annotations by enumerating the exact return shape (user_id, status, via, joined_at, roles[], teams[], user object) and the error condition for non-members. This is strong but not exhaustive; it doesn't mention pagination, but that is not relevant for a single-record read.

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 composed of three sentences, all carrying substantive information: what the tool does, what it returns/errors, and how it relates to sibling tools. It is front-loaded with the core purpose and contains 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 operation with strong annotations, the description is complete. It specifies the input key, the output fields, the error condition, and the relationship to sibling tools. No output schema is present, but the description supplies the necessary return information.

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%, and the schema already explains that `id` is the user ID (`usr_…`) and that there is no separate membership ID. The description reinforces 'USER id' but adds no new parameter meaning beyond what the schema provides, so the baseline of 3 is appropriate.

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 opens with a specific verb and resource ('Read one membership by USER id'), which clearly identifies what the tool does. It also differentiates itself from sibling tools by emphasizing that it returns a single membership record and by referencing member.list and member.set_roles explicitly.

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 provides direct usage guidance: use member.list with `q` to find someone by name first, and read this before member.set_roles. It also clarifies the error condition (user not a member of this organization), giving the agent clear context for when this tool is appropriate.

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