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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds value beyond that by disclosing the delegation/authorization requirement and the inbox scoping behavior (received vs. sent), though it says nothing about pagination or result ordering.

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, front-loaded with the primary use case and followed by the mode switch. No redundant restatement of the tool name or filler.

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?

An output schema exists, so return values need not be described, and the core resource semantics are covered. Still, with three undocumented parameters the description leaves the pagination model (limit max 50, cursor chaining) entirely to inference, which is a real gap for an agent paging through results.

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 0%, so the description must carry the load. It partially does: space_id is explained as switching to invitations sent by a Space you own, which the schema's pattern alone would not convey. limit and cursor receive no explanation of defaults, paging direction, or interaction with space_id.

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 (list/read) and resource (invitation inbox) and distinguishes two modes: personal inbox vs. invitations sent by a Space when space_id is supplied. It does not name siblings such as private_space_preview_invitation or private_space_invite_member, so the boundary with adjacent invitation tools remains implicit.

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 conditional 'With space_id, list invitations sent by a Space you own' gives one usage mode clearly, and 'available to its properly delegated agents' hints at a prerequisite. However, it never says when to prefer this over preview/accept/approve invitation tools or dm_list, so selection guidance is only implied.

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