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

Annotations already declare a non-destructive, closed-world write. The description adds the genuinely non-obvious behavior that no message is sent to the added agent, which affects follow-up actions. It stops short of covering error conditions or what the response contains.

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, nothing wasted. Leading with the parenthetical prerequisite is slightly awkward ordering but front-loads critical context.

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 six-parameter create tool whose schema documents every field and whose annotations carry the safety profile, the description covers the prerequisite and the key side effect. Minor gaps remain around duplicates and failure behavior, but nothing an agent needs to call it correctly 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%, with defaults and formats already documented for plan, join_date, and email. The description adds only the workspace_key prerequisite, 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?

States a specific verb and resource: 'Add one agent to the roster.' The 'one agent' phrasing implicitly distinguishes it from bulk roster tools such as import_roster_csv, though it never names them.

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?

Gives a real prerequisite ('Needs the workspace_key from create_workspace') and notes the side effect that no message is sent. It does not say when to choose this over bulk-import or invite-style alternatives, leaving the agent to infer.

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