perseus

perseus_waypoint

Read-only

Retrieve the last session checkpoint to resume work, including task details, status, and next steps. Automatically expires after 24 hours.

Instructions

Return the most recent session checkpoint: what was being worked on, status, and next steps. Use at session start to resume where you left off. Stale after TTL (default 24h). Read-only; lightweight — call freely.

Tool call template

This tool declares no required parameters. Add optional parameters from the input schema as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {},
    "name": "perseus_waypoint"
  }
}

Input Schema

Name	Required	Description	Default
`ttl`	No	Max age in seconds for a valid checkpoint (default: 86400)

Output Schema

Name	Required	Description
`stale`	No	Whether the checkpoint exceeds TTL
`timestamp`	No	ISO-8601 timestamp of checkpoint
`checkpoint`	No	Latest checkpoint summary text

Schema Changelog

Changes observed during successful MCP inspections.

Changed2 schema fields changedv1.0.7Jun 10, 2026

changedInput schema / properties / ttl / description

Previous value: -"ttl= modifier for @waypoint"New value: +"Max age in seconds for a valid checkpoint (default: 86400)"

changedOutput schema / (root)

Previous value: -nullNew value: +{
+  "properties": {
+    "checkpoint": {
+      "description": "Latest checkpoint summary text",
+      "type": "string"
+    },
+    "stale": {
+      "description": "Whether the checkpoint exceeds TTL",
+      "type": "boolean"
+    },
+    "timestamp": {
+      "description": "ISO-8601 timestamp of checkpoint",
+      "type": "string"
+    }
+  },
+  "type": "object"
+}

First observedv0.1.0May 27, 2026

TDQS

A4.2/5.0

Behavior4/5

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

Annotations already indicate read-only; description adds 'lightweight' and 'call freely' for safe invocation. Also notes staleness after TTL, adding behavioral context beyond annotations.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

Two sentences, no wasted words. Purpose is front-loaded, followed by usage and behavioral notes. Highly efficient.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness4/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given output schema exists, the description adequately summarizes return content. Parameter is documented. No major gaps.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema has 100% coverage for the single parameter (ttl). Description reinforces the TTL concept but does not add new meaning beyond the schema description.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states it returns the most recent session checkpoint, specifying content: what was being worked on, status, and next steps. This distinguishes it from sibling tools like perseus_session or perseus_memory.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines4/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

Explicitly advises use at session start to resume progress. Mention of staleness and default TTL provides context. No explicit when-not-to-use, but the specific purpose makes it clear.

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