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

Annotations only carry destructiveHint=true; the description adds substantial context beyond that: it is explicitly a write, it is a partial/patch-style update rather than a full replace, `tags` is a destructive full-list replacement, and it names the required OAuth scope (flex.community.members.update) plus the underlying endpoint. That is exactly the extra disclosure annotations cannot provide.

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 tight sentences with the WRITE flag front-loaded, then capability scope, then the critical partial-update caveat, then auth/endpoint metadata. No filler and nothing buried at the end that should be first.

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 9-parameter, nested-object write tool with no output schema, the description covers the operation type, partial-update semantics, destructive tag behavior, and auth scope. It stops short of stating failure modes (unknown member_id, invalid custom property) or what a successful response returns, but nothing essential to calling 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 description coverage is 100% and every parameter is individually documented, so the schema already carries the load. The description's field list and the `tags` replacement note largely restate what the schema says ('Replaces the member's entire tag list.'), so it adds little on top. Baseline 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?

States a specific verb (Update) and resource (a member) and enumerates the exact mutable surface: name, email, phone, start date, billing/contact flags, tags, custom properties. Combined with the WRITE marker, an agent can distinguish this from officernd_create_member and officernd_get_member without opening any schema.

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?

It discloses the key operational rule — 'Only the fields you pass are changed' — which tells the agent how to invoke it, and gives the required scope. But it never contrasts with siblings (e.g. create_member to add, get_member to read) nor states when an update is the wrong choice. Usage is implied rather than stated.

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