teams_add_group_member

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

Annotations already declare readOnlyHint=false and destructiveHint=false, so the description is free to add the part that matters: the added person gains visibility of the chat, which is a real privacy consequence not encoded anywhere in the schema or annotations. The 'confirm who first' instruction is also a useful operational constraint. It stops short of stating what happens on duplicate membership or permission failures.

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?

Two short sentences, front-loaded with the capitalized action verb, with the effect in parentheses and the usage constraint last. Nothing is padded.

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 2-parameter mutation with no output schema and annotations covering the safety profile, the definition covers purpose, side effect, and a confirmation gate. Remaining gaps (duplicate-member behavior, error surface, how to obtain the member id) are modest but real.

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 50%: 'member' carries a Teams id example, but 'conversationId' has no schema description at all. The description scopes the operation to a group chat, which partially disambiguates conversationId, yet it never explains that the member must be a Teams user id resolvable via the sibling lookup tools.

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 ('ADD a person to a group chat') and adds the consequence '(they can see the chat)', which tells the agent this is a membership mutation, not a message send. It is naturally distinct from teams_remove_group_member and teams_add_reaction, but it never names a sibling to sharpen the boundary.

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?

'Only when the user asked; confirm who first' gives an explicit gating condition plus a required pre-step (verify the identity). What's missing is routing guidance: nothing says to use teams_create_group_chat when no group exists yet, or teams_get_chat_members to resolve the member id.

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