contacts_modify_group_members

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

No annotations are present, so the description carries full burden. It only states the action without disclosing behavioral traits such as whether duplicates are allowed, whether both add and remove can be specified simultaneously, what happens if a contact doesn't exist, or error behavior. For a mutation tool, this is insufficient.

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 a single, front-loaded sentence with zero wasted words. It is very concise, though slightly too terse for a tool with three parameters and mutation semantics, but that is a completeness issue, not a conciseness one.

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?

Given the tool has 3 parameters, mutation semantics, and no annotations, the description is inadequate. It does not cover required vs optional parameters, interaction between add_contacts and remove_contacts, or return value expectations. Even with an output schema present, the description leaves too many operational gaps.

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 0%. The description does not explain parameter semantics beyond echoing 'add' and 'remove'. It fails to specify that add_contacts and remove_contacts are arrays of contact resource names, or how group_resource_name should be formatted, adding minimal value over the bare schema.

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 clearly states the tool's function with specific verbs ('add', 'remove'), a resource ('contacts'), and a target ('contact group'). It distinguishes from sibling contact tools like contacts_batch_create/delete which operate on contacts themselves, not group membership.

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?

No guidance is provided on when to use this tool versus alternatives. There is no mention of prerequisites such as retrieving group_resource_name via contacts_list_groups or obtaining contact resource names from contacts_search, nor any indication of when modification is preferred over recreation.

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