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

Annotations cover the safety profile (destructiveHint=false, readOnlyHint=false, openWorldHint=true), so the burden is lighter, and the description still adds real value: no invitation email is sent, and there is an admin-only path for admin roles. It does not address behavior on a duplicate invite or whether the pending invite has an expiry, which idempotentHint=false makes relevant.

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?

Three short sentences, zero padding, and the tool's core action plus its most surprising trait (no email is sent) are front-loaded in the first two sentences.

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 three-parameter mutation with full schema coverage and no output schema, the description supplies the permission model and the no-email caveat, which is enough to call it correctly. It could go slightly further on duplicate-handling behavior given idempotentHint=false, but nothing essential 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 description coverage is 100%, so email, role, and teams are already documented with an enum and a default. The description only gestures at role semantics ('Only admins can invite admins') and adds no syntax or behavioral detail about the teams parameter or the default role. 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 states a specific verb and resource ('Create a pending workspace invitation for an email address') and immediately qualifies the scope with 'pending' and the crucial negative 'does not send an invitation email'. This distinguishes it from sibling mutation tools like add_team_member, which presumably adds an already-existing user.

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?

'Requires a role that can invite members. Only admins can invite admins.' gives clear permission prerequisites and a role-escalation rule. However, it never names an alternative or states when NOT to use this tool (e.g., inviting someone already in the workspace), so it stops short of full routing guidance.

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