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

Annotations already indicate idempotentHint=true and readOnlyHint=false, but the description adds meaningful behavioral details: it requires admin access, changes account access, and does not send an invitation email. These specifics go beyond the annotations and help the agent understand side effects and prerequisites.

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 concise and front-loaded with the core action, then follows with key behavioral constraints. Every sentence earns its place—no filler or repetition. It efficiently conveys the purpose, prerequisite, and side effects.

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 that an output schema exists, the description does not need to explain return values. It covers all essential call details: purpose, admin requirement, side effects (no email), and the optional project assignment. The idempotency key is documented in the schema, so nothing critical is missing for correct invocation.

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 80%, so most parameters are already documented. The description adds minimal parameter semantics beyond the schema—only the optional assignment to a project is echoed. It does not introduce new meaning, so baseline 3 is appropriate.

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 verb 'Add' and the resource 'team member', and explicitly mentions optional assignment to a project, distinguishing it from the sibling 'assign_team_member' which likely deals with existing members. This is a specific, non-tautological purpose.

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 description provides clear context for use: it requires administrative access and explicitly notes that no invitation email is sent. However, it does not state when to use an alternative like assign_team_member (e.g., when the member already exists), only the conditions for this tool. This meets the 'clear context, no exclusions' level.

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