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

Annotations only declare readOnlyHint and openWorldHint; the description adds the real behavioral context: no account or login required, requests are browser-minted signed requests, tokens are short-lived and a stale token surfaces as an upstream error, and each comment yields at most five replies. That is substantive disclosure beyond the annotation surface.

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?

Front-loaded with the verb and resource, then input paths, then return shape, then failure handling — a logical order with no filler. The return-value enumeration is long, though it remains informative rather than redundant padding.

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?

Covers auth posture, both input forms, token staleness and its recovery, pagination via has_more/cursor, and the boundary of what the API exposes. With an output schema present, the return-value prose is optional but the description still leaves no ambiguity about correct invocation.

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 documents the URL/note_id/xsec_token either-or relationship and the cursor. The description reinforces the coupling (URL 'carries the required xsec_token') but adds little format or constraint detail the schema lacks, so it sits at the baseline for a fully documented schema.

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 ('Fetch one page of a public Xiaohongshu note's comments') plus the scope constraint ('one page'), and distinguishes itself from xiaohongshu_explore and xiaohongshu_note by naming the sibling that produces its input. An agent can tell immediately what this tool returns and what it does not.

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?

Gives explicit input paths ('Pass the note_url returned by xiaohongshu_explore ... or pass note_id plus xsec_token directly') and an explicit exclusion ('search results and profiles require login and are not exposed'), which tells the agent when not to reach for this tool. It also prescribes the remediation path for a stale token, leaving nothing to inference.

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