WebMCP Blog Posts Filter Tool

WebMCP Blog Posts Filter Tool

Status

Draft - awaiting review

Background

The site has a blog section (docs/blog/) with posts in German and English. Filtering by date range is a natural agent use case: “show me posts since X date” or “what was posted this week?”

Problem

• Blog posts are chronologically ordered but not queryable by date range
• Agent would need to scan all posts and filter client-side

Goal

WebMCP tool get_posts_since() returns posts published after a given date.

User Stories

US-1: Recent Posts Query

As an agent, I want to fetch blog posts published since a specific date.

Acceptance Criteria:

• Agent calls get_posts_since(date) with ISO date string
• Tool returns posts with publish date >= requested date
• Each result: title, slug, date, language hint

Functional Requirements

ID	Requirement
FR-001	Tool name: get_posts_since
FR-002	Input: date parameter (ISO 8601 date string, e.g., “2026-07-01”)
FR-003	Output: JSON array { title, slug, date, lang }
FR-004	readOnlyHint: true
FR-005	Date comparison is inclusive (posts ON that date included)

Design

Tool Registration

const BLOG_POSTS = [/* build-time Astro collection */];

document.modelContext.registerTool({
  name: "get_posts_since",
  description: "Get blog posts published on or after a specific date. Returns title, slug, date, and language.",
  inputSchema: {
    type: "object",
    properties: {
      date: {
        type: "string",
        format: "date",
        description: "ISO 8601 date (e.g., 2026-07-01)"
      }
    },
    required: ["date"]
  },
  execute: async ({ date }) => {
    const since = new Date(date);
    const matches = BLOG_POSTS
      .filter(p => new Date(p.date) >= since)
      .map(p => ({ title: p.title, slug: p.slug, date: p.date, lang: p.lang || "en" }));
    return matches.sort((a, b) => new Date(b.date) - new Date(a.date));
  },
  annotations: { readOnlyHint: true }
});

Test Plan

Test	Input	Expected
Future date	“2027-01-01”	Returns []
Past date	“2025-01-01”	Returns all posts
Specific date	“2026-07-06”	Returns posts from that date onward

Links

• Blog directory