Skip to main content
Glama
julcap

nginx-certbot-mcp

by julcap
OverviewSchemaSourceRelated ServersDiscussionsAdmin
TypeScript
Local

issue_cert

Request a Let's Encrypt certificate for a domain with an existing nginx server block. Uses HTTP-01 validation, adds SSL and HTTP-to-HTTPS redirect to the config, and defaults to staging; set staging:false for a production certificate.

Instructions

Request a certificate via certbot --nginx (HTTP-01 validation). Requires an nginx server block for domain to already exist (create_site) - certbot's nginx plugin edits that existing sites-available config in place, adding an SSL server block and an HTTP->HTTPS redirect; it does not create a new site from scratch, and it reloads nginx itself on success (no separate reload_nginx call needed). Pre-checks that the domain resolves and fails fast with guidance if not, avoiding a wasted attempt against Let's Encrypt's rate limits. Defaults to Let's Encrypt staging, which issues browser-untrusted certs but is exempt from rate limits - pass staging:false only when you're ready for a real, publicly CT-logged certificate: production Let's Encrypt enforces real per-domain issuance rate limits (a handful of certs per week), and a mis-issued cert isn't silently undone - call revoke_cert if you need to invalidate one. For a *.domain wildcard, use issue_wildcard_cert instead - HTTP-01 can't validate wildcards.

Input Schema

TableJSON Schema
NameRequiredDescriptionDefault
emailNoContact email registered with the Let's Encrypt account, used for renewal-failure and expiry notices. Omitted registers with --register-unsafely-without-email, so Let's Encrypt cannot warn you if a future automated renewal fails.
domainYesDomain to request a certificate for. Must already resolve (see check_dns) and already have an nginx server block from create_site - certbot edits that existing config rather than creating one.
stagingNoTrue (default) uses Let's Encrypt's staging CA - browser-untrusted certs, but exempt from production rate limits; use for testing the flow. False requests a real, browser-trusted cert and counts against production rate limits.

Output Schema

TableJSON Schema
NameRequiredDescriptionDefault
successYes
dns_checkNoPresent only when the DNS pre-check failed, before certbot was even invoked
certbot_outputYesRaw combined stdout/stderr from the certbot CLI invocation, on success or failure

Schema Changelog

Changes observed during successful MCP inspections.

  1. Changed5 schema fields changedv0.1.1
    • removedInput schema / additionalProperties
      Removed value: -false
    • addedInput schema / properties / domain / description
      Added value: +"Domain to request a certificate for. Must already resolve (see check_dns) and already have an nginx server block from create_site - certbot edits that existing config rather than creating one."
    • addedInput schema / properties / email / description
      Added value: +"Contact email registered with the Let's Encrypt account, used for renewal-failure and expiry notices. Omitted registers with --register-unsafely-without-email, so Let's Encrypt cannot warn you if a future automated renewal fails."
    • addedInput schema / properties / staging / description
      Added value: +"True (default) uses Let's Encrypt's staging CA - browser-untrusted certs, but exempt from production rate limits; use for testing the flow. False requests a real, browser-trusted cert and counts against production rate limits."
    • changedOutput schema / (root)
      Previous value: -nullNew value: +{
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "additionalProperties": false,
+  "properties": {
+    "certbot_output": {
+      "description": "Raw combined stdout/stderr from the certbot CLI invocation, on success or failure",
+      "type": "string"
+    },
+    "dns_check": {
+      "additionalProperties": false,
+      "description": "Present only when the DNS pre-check failed, before certbot was even invoked",
+      "properties": {
+        "record_type": {
+          "description": "Only present when resolves is true",
+          "enum": [
+            "A",
+            "AAAA",
+            "CNAME"
+          ],
+          "type": "string"
+        },
+        "resolves": {
+          "type": "boolean"
+        },
+        "values": {
+          "description": "Resolved values (IPs, or the CNAME target); only present when resolves is true",
+          "items": {
+            "type": "string"
+          },
+          "type": "array"
+        }
+      },
+      "required": [
+        "resolves"
+      ],
+      "type": "object"
+    },
+    "success": {
+      "type": "boolean"
+    }
+  },
+  "required": [
+    "success",
+    "certbot_output"
+  ],
+  "type": "object"
+}
  2. First observedv0.1.0

TDQS

A5/5.0
Behavior5/5

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

Annotations provide openWorldHint=true and destructiveHint=false, but the description goes far beyond that. It discloses that the tool edits existing config, reloads nginx, pre-checks domain resolution and fails fast, defaults to staging (which issues untrusted certs but avoids rate limits), and warns that production issuance has real rate limits and that revoke_cert is needed to invalidate a mis-issued cert. This is rich behavioral context not available in annotations or schema.

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?

Although the description is a single long paragraph, it is tightly packed with actionable information. It front-loads the core action, then covers prerequisites, behavioral notes, staging nuance, and the wildcard alternative. There is no redundancy or filler; every sentence adds value and the flow is logical.

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

Completeness5/5

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

The tool is a mutation with external dependencies (Let's Encrypt) and rate-limit considerations. The description covers prerequisites (existing server block), behavior (edits config, reloads nginx), staging vs production, rate limits, revocation fallback, and wildcard routing. An agent has everything it needs to decide whether and how to call this tool correctly. The output schema exists, so return-value details are not required.

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

Parameters5/5

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

Schema description coverage is 100%, so baseline is 3, but the description adds substantial meaning beyond the schema. For email, it explains the consequence of omission (no renewal warnings). For domain, it reiterates the prerequisite of an existing server block and points to check_dns. For staging, it elaborates on the trade-offs between staging and production, including rate limits and CT-logging. The description genuinely enhances parameter understanding.

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 opens with a specific verb and resource: 'Request a certificate via `certbot --nginx` (HTTP-01 validation).' It clearly states what the tool does and distinguishes it from the sibling issue_wildcard_cert, which is explicitly named for wildcard domains. The purpose is unambiguous and differentiated.

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

Usage Guidelines5/5

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

The description explicitly states when to use this tool: it requires an existing nginx server block from create_site, and it notes that certbot edits that config in place and reloads nginx itself, so no separate reload_nginx call is needed. It also names the alternative for wildcards (issue_wildcard_cert) and explains why HTTP-01 can't validate wildcards, providing clear exclusion criteria.

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