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

Annotations already declare this is a non-read-only, non-destructive, non-idempotent write with no open-world access. The description goes beyond them with real operational context: no login is provisioned, nobody is emailed, and the call returns a teamMemberId. It stops short of explaining duplicate handling, which matters given idempotentHint=false.

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?

Four short sentences, each carrying a distinct fact: what it does, the no-email behavior, the alternative tool, the internal-only flag, the return value. Lead sentence is the most important and 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?

An output schema exists, so the description needn't enumerate return fields, yet it still names teamMemberId. Combined with the no-login/no-email disclosure and the explicit sibling routing, an agent has everything needed to select and invoke this correctly against a 5-param schema.

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 60% (email and isInternalOnly documented; firstName, lastName, timezone bare). The description reinforces isInternalOnly's meaning but adds nothing for timezone format, name constraints, or what email is used for beyond the schema's own note. Baseline 3 applies since the schema carries most of the load.

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 ('Adds a person to the connected Nexwin account's team') plus the defining constraint that no login is created. The sibling tool invite_team_member is named directly, so an agent can separate the two without reading either 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?

Explicit routing rule: 'Use invite_team_member instead if they need to sign in.' It also gives a per-parameter usage rule for isInternalOnly ('someone callers should never be told about by name'), covering both tool selection and option selection.

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