Skip to main content
Glama
Sign In
umbra

umbra

by lxchx
OverviewSchemaSourceRelated ServersDiscussionsAdmin
Python
Remote

Har Replay Load

har_replay_load

Load HAR files or raw JSON into a replay corpus so matching requests are served from recorded entries instead of the network.

Instructions

Load a HAR file (path) or raw JSON string (har_json) into the replay corpus. Subsequent matching requests (method+url, or url-only when loose=True) are fulfilled from the HAR entry instead of hitting the network. Replay is fallthrough — it only fires on requests no route_add rule already matched.

Ex: har_replay_load('t0', path='/tmp/session.har') → {"loaded":42,"loose":false} Ex: har_replay_load('t0', har_json='{"log":{"entries":[...]}}', loose=True) → {"loaded":N,"loose":true,"total_loaded":N}

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "tab_id": "<tab_id>"
    },
    "name": "har_replay_load"
  }
}

Input Schema

NameRequiredDescriptionDefault
pathNo
looseNo
tab_idYes
har_jsonNo
clear_existingNo

Output Schema

NameRequiredDescriptionDefault

No arguments

Schema Changelog

Changes observed during successful MCP inspections.

  1. First observedv0.1.0

TDQS

A4.1/5.0
Behavior4/5

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

No annotations, so the description carries the full burden, and it does a lot: it discloses the fallthrough precedence against `route_add`, the matching key (method+url vs url-only under loose), and gives concrete response shapes with `loaded`/`total_loaded`. The notable gap is `clear_existing` — the description never says whether loading a HAR replaces or appends to the existing corpus, which is the main destructive-behavior question here.

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

Conciseness4/5

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

Front-loaded with the purpose, then semantics, then two compact usage examples that are genuinely illustrative rather than filler. Slightly dense in the middle paragraph but no sentence is wasted.

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?

Output schema exists, so return values needn't be explained, and the examples supplement them anyway. Given no annotations and a stateful corpus-mutating tool, the description covers precedence, matching, and inputs well; the missing piece is what happens to previously loaded entries when a new HAR is loaded.

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 coverage is 0%, so the description must compensate, and it meaningfully explains `path`, `har_json`, `loose`, and the implied `tab_id` in the examples. However `clear_existing` is entirely absent and no mutual exclusivity between `path` and `har_json` is stated, leaving roughly one of five parameters undocumented in both places.

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?

States a specific verb and resource: load a HAR file or raw JSON into the replay corpus, with two input modes named. It also distinguishes itself from the routing siblings by explaining that replay is fallthrough behind `route_add`, so an agent can place it relative to `har_record_start`/`har_dump`/`route_add` without opening a schema.

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?

Clearly says when replay fires (subsequent matching requests instead of the network) and the key condition that governs it (only when no `route_add` rule matched). It does not explicitly say when to prefer this over sibling HAR tools like `har_record_start`, so it stops short of full when/when-not coverage.

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

Deploy Server

Other Tools