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

Beyond annotations (readOnlyHint=false, destructiveHint=false), the description adds two useful behavioral facts: createTeamInvite has no mail side effect, and the accept link is always derived from the server-configured app origin, so frontendUrl cannot override it. It does not detail auth/rate limits or post-send state changes, but the primary side effect—sending an email—is explicit.

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 sentences, each with a distinct job: main action, when to use, and server-origin constraint. No filler or duplication of schema content. The most important information is front-loaded.

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 single-object send action with only three parameters and no output schema, the description covers what the tool does, when to use it, its relationship to createTeamInvite, and a key behavioral constraint. It does not specify return/error behavior or what happens if the invitation was already sent, but these are minor for a tool of this complexity.

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%, and the schema already explains id, team_id, and the deprecated ignored frontendUrl. The description reinforces the id semantics contextually and explains why frontendUrl is irrelevant, but it does not add substantial param-level meaning beyond the schema. 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 opens with 'Email an invitation to its recipient,' naming a specific verb and object. It further distinguishes itself from createTeamInvite by stating that tool never sends mail on its own, and clarifies that this tool also handles resending. This is enough for an agent to differentiate it from siblings like listTeamInvites or bulkCreateTeamInvites.

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?

It explicitly instructs when to use: to deliver an invitation created by createTeamInvite or to resend one the recipient never received. It names createTeamInvite as the companion creation tool that does not send mail, providing an alternative and the condition that selects this tool. The guidance is clear and actionable.

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