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

Annotations already declare readOnlyHint and idempotentHint, so the safety profile is covered. The description contributes real behavioral context beyond them by specifying the returned fields and explicitly noting that full article text is NOT included, which prevents an agent from promising full content. Auth, rate limits, and pagination behavior remain unmentioned.

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 sentences, no filler. The return-shape clause is placed before the usage clause, so an agent reading top-down learns what it gets and then when to reach for it.

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?

With no output schema, the description carries responsibility for describing return values and does so concretely (title, slug, summary, category, timestamps, source URL, plus the exclusion of full text). For a simple read-only list tool with a fully documented schema, this is close to complete; only pagination/ordering guarantees are absent.

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 every parameter (limit, since, category, language) is already documented with defaults and formats. The description adds no per-parameter meaning, so the baseline 3 applies.

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 gives a specific verb and resource ('Get the latest published Vaper.club posts') and enumerates the covered content types (news, reviews, guides). The word 'latest' implicitly separates it from search-style siblings like search_posts, but the distinction is not stated outright, so it stops short of a full 5.

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?

'Use when users ask for recent vape industry news or articles' gives a clear triggering condition tied to recency-oriented requests. It lacks any negative guidance or an explicit pointer to search_posts for keyword/query-based retrieval, leaving that routing decision to inference.

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