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

Beyond the annotations (readOnlyHint=false, destructiveHint=false), the description discloses important behavioral details: the invitation remains pending, no email is sent, and admin invites are restricted to admins. These traits materially affect expectations and are not inferable from the schema or annotations alone.

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 with no wasted words. The core action, a key non-behavior (no email), and permission constraints are all front-loaded and each sentence earns its place.

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 tool with no output schema, the description covers the essential purpose, side-effect profile, and authorization requirements. It leaves minor edge cases unspecified, such as duplicate invites or the acceptance flow, but those are not necessary for correctly invoking the tool.

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 the baseline is 3. The description adds value by clarifying role-based permission semantics that the schema does not encode, specifically that only admins can invite admins. It does not need to repeat the schema's documentation of email, role, or teams.

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 uses a specific verb and resource: 'Create a pending workspace invitation for an email address.' It is clearly distinct from sibling tools like add_team_member because it focuses on a pending workspace-level invitation rather than adding an existing member to a team. The additional clarification that no invitation email is sent further sharpens the 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 when to use this tool: when creating a pending invitation by email. It also states authorization requirements, including 'Requires a role that can invite members' and 'Only admins can invite admins.' It does not explicitly name alternative tools or exclusion conditions, but the context is strong enough for an agent to make a correct selection.

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