Add Space Members

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

Annotations already declare readOnlyHint=false and destructiveHint=false; the description adds genuinely new context by stating the operation is additive-only (existing roles are preserved) and requires space admin rights. It does not explain behavior on invalid emails/ids or partial batch failures, which would be the remaining gap for a mutation tool.

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, zero filler, with the core action first, the identity-format note second, and the disambiguation plus prerequisite last. Every clause carries information an agent needs.

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?

An output schema exists so return values need no explanation, and auth requirements, idempotency semantics and the sibling alternative are all covered. Only batch-size behavior and failure handling are unaddressed, which keeps it just below fully complete.

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 all four parameters are already documented upstream. The description restates the user/group identifier formats (email or id, name or id) that the schema already carries, adding no syntax or constraint detail beyond it — 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+resource+effect: 'Give users and groups a role in a space.' It also names the sibling it must not be confused with (change_space_member_role), so an agent can discriminate it from the adjacent role-mutation tool without reading 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?

Gives a clear when-not ('People who already have a role keep it') plus the explicit alternative ('use change_space_member_role for them') and the prerequisite ('Needs admin rights in the space'). It stops short of covering edge conditions such as what happens on partial failure or the 25-item batch limit, so it is strong but not exhaustive.

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