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

No annotations exist, so the description carries the burden and does well: it discloses that comments live beside the design, are never in the document, invisible to exports, that `acknowledgedBy` tracks read state, and that `sequence` rises on each change. Missing auth/permission notes and rate/pagination behavior, but the persistence and state semantics are strong.

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?

One dense paragraph, front-loaded with the core definition, then the cursor/persistence details. Every sentence carries information, though the persistence sentence could be tightened slightly.

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-value explanation is unnecessary and correctly omitted. The description supplies the behavioral and routing context an agent needs; only auth requirements and cursor-format specifics are left implicit.

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?

Two parameters at 50% schema coverage. The `token` parameter is richly documented in the schema itself, and `designId` is self-evident. The description adds no parameter-level meaning, so this lands at the baseline for schema-covered params.

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 and resource ('Read the discussion on a design') and enumerates what a thread contains (pinning location, resolved state, replies). It cleanly distinguishes itself from ui_builder_await_comments by describing `sequence` as the cursor to quote to that sibling.

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?

Clearly routes the agent: use `sequence` with ui_builder_await_comments and mark reading done via ui_builder_acknowledge_comment. Context for use is explicit, though it never states a when-not condition (e.g., 'use await_comments instead of polling this repeatedly').

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