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

Annotations only declare readOnly=false, destructive=false and openWorld=true; the description adds genuinely new behavior — that an invite email is actually sent as a side effect and that the call fails for existing members. It omits whether invites expire, what role assignment implies, or auth requirements, keeping it below 5.

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, zero filler, with the action stated first and the failure condition second. Nothing could be removed without losing information.

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 simple two-parameter mutation with an output schema already present, the description covers purpose, side effect, and failure mode adequately. Minor gaps remain around permissions required to invite and any role restrictions, but no essential calling information 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 coverage is 100%, so the schema already documents both 'email' and the role enum with its default. The description only echoes the email channel and adds no format, validation, or role-capability meaning beyond the schema, matching the baseline 3.

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 states a specific verb and resource ('Invite a user to the organization's team') plus the channel ('by email'), which is clearly distinct from sibling tools like list_team_members, get_team_member, and update_team_member. It stops short of naming a sibling for contrast, so it lands at 4 rather than 5.

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?

The clause 'fails if they are already a member' gives a useful precondition for when this call is appropriate, but there is no explicit routing guidance (e.g., what to do instead for an existing member, or any prerequisite permissions). Usage is implied rather than spelled out.

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