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

With no annotations provided, the description carries the burden and does well: it discloses that this is a restrictive write, requires admin privileges, has an exception carve-out for owners/admins, and that null means unrestricted access. It stops short of saying whether the list fully replaces prior access or merges with it, which matters for a permissions mutation.

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, front-loaded with the core semantics, then the one non-obvious enum, then the access preconditions. No filler and every clause conveys information an agent needs before calling.

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 with no annotations and no output schema, this covers purpose, value semantics, and authorization limits well. The remaining gap is replacement vs. merge behavior on an existing allow-list, which an agent would want to know before overwriting a member's access.

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%, so the baseline is 3, but the description adds genuine value beyond the schema by explaining what the otherwise opaque enum value 'crm-contact-details' actually gates (lead emails/phones). The null/full-access explanation duplicates the schema's own text, so it earns no extra credit.

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 ('Restrict what a (non-admin) member sees') and immediately defines the core data shape: an allow-list of features, or null for full access. The scope is clear enough to distinguish it from role-management siblings like set_workspace_member_role, though it never names that sibling 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?

Gives real applicability constraints: only non-admin members can be targeted, the caller must be an admin, and the owner and admins cannot be restricted. It does not mention the related preview_set_workspace_member_role flow or explicitly route the agent away from set_workspace_member_role, so the when-to-use picture is clear but not fully differentiated.

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