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

Annotations are all-false and carry almost no signal, so the description carries the full burden — and it delivers: it discloses that the call bypasses the vetting queue, refuses callers not on the frozen list, mutates the roster, requires the organizer role, and that registration is separate from attending (NDA must still be signed). No contradiction with the annotations; readOnlyHint=false is consistent with the described write behavior.

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?

Well-structured with front-loaded purpose and a logical flow: exclusion → override case → self-serve case → refusal → role → NDA → args → member_id trap → returns → scope. It is lengthy and there is minor redundancy (organizer requirement stated in title, body, and scope line), but every sentence earns its place given the parameter traps it must warn against.

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?

Complete despite no output schema — returns { ok, role, seats } are specified. It covers the role gate, required scope, refusal behavior, the self-serve edge case, the NDA dependency, and the member_id identity trap. Only eid's meaning is left implicit, but the title and 'this event' wording make it inferable. Nothing an agent needs to call this 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 80%, but the description adds critical semantics absent from the schema: member_id is a CLERK USER ID (user_...), not an email; it names SOMEBODY ELSE; omitting it acts on yourself; passing your own email routes down the organizer path and refuses. It also clarifies that display_name/org/sponsor_visible are recorded on the self-serve path. These warnings prevent a genuinely likely misuse and go well beyond the schema's 'Who to seat. Defaults to the calling member.'

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?

Opens with a specific verb+resource: 'Put a member straight onto the roster as a PARTICIPANT, bypassing the application queue.' It explicitly contrasts itself with ic_hack_application_form and ic_hack_apply, and the title adds the organizer-only walk-in framing. An agent can distinguish this from the application/check-in siblings without opening any schema.

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?

States when-not explicitly: 'This is NOT the front door any more... the way in is ic_hack_application_form then ic_hack_apply, and a human decides.' It then gives the two legitimate use cases (organizer walk-in override, frozen-door-list self-serve) and names the NDA sibling (ic_hack_sign_nda) required for attendance. Selection guidance is unambiguous and complete.

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