communitiesList communities on a Lemmy instance (default lemmy.world), sortable by Active/Hot/New/TopMonth/etc. and filterable by type (All/Local/Subscribed). Returns community name, description, and subscriber count.
| Name | Required | Description | Default |
|---|---|---|---|
| page | No | ||
| sort | No | ||
| limit | No | ||
| type_ | No | ||
| instance | No |
| Name | Required | Description | Default |
|---|---|---|---|
| communities | No | List of communities |
Changes observed during successful MCP inspections. Dates show when Glama detected each change.
Input schema / examplesAdded value: +[
+ {
+ "limit": 25,
+ "sort": "Active"
+ },
+ {
+ "instance": "lemmy.world",
+ "page": 2,
+ "type_": "Local"
+ }
+]Output schema / (root)Previous value: -nullNew value: +{
+ "description": "Response from Lemmy API /community/list endpoint",
+ "properties": {
+ "communities": {
+ "description": "List of communities",
+ "items": {
+ "properties": {
+ "community": {
+ "description": "Community object with id, name, title, description",
+ "type": "object"
+ },
+ "counts": {
+ "description": "Community statistics (subscribers, posts, comments)",
+ "type": "object"
+ }
+ },
+ "type": "object"
+ },
+ "type": "array"
+ }
+ },
+ "type": "object"
+}Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint=false. The description adds useful behavioral context by specifying the exact return fields (name, description, subscriber count) and sort/filter capabilities, going beyond the annotations.
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 efficient sentences, front-loaded with the core action. Every clause adds value (default instance, sort/filter options, return fields) with no redundant wording.
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?
For a simple read-only list tool with an output schema, the description covers the essential aspects: purpose, default instance, sort/filter options, and return fields. It could mention pagination behavior of page/limit, but the output schema plus annotations make it sufficiently complete. Not perfect, but solid.
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 has 0% parameter descriptions, so the description must compensate. It explains the semantics of 'sort' (Active/Hot/New/TopMonth/etc.), 'type_' (All/Local/Subscribed), and 'instance' (default lemmy.world), but does not address 'page' or 'limit', which are non-obvious. Partial guidance, so baseline 3.
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 clearly states the tool's function: 'List communities on a Lemmy instance', with specific sorting and filtering options. It distinguishes from the sibling tool 'community' (singular) by explicitly pluralizing and listing features.
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?
Provides clear context for when to use the tool (listing communities), including default instance and available filters/sorts. However, it does not explicitly mention alternatives or exclusions, such as when to use 'community' instead.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Add one secure layer between your agents and this server.
Many tools have overlapping purposes: ask_pipeworx, ask_pipeworx_beta, ask_pipeworx_grounded, deep_research, and validate_claim all answer factual questions, while bet_research, polymarket_edges, polymarket_arbitrage, and polymarket_fill_risk all analyze prediction markets. The Lemmy tools are distinct from the Pipeworx tools, but within each cluster an agent could easily select the wrong tool despite lengthy descriptions.
Naming conventions are mixed: single nouns (post, community, site), verb_noun patterns (list_subscriptions, resolve_entity, generate_llms_txt), and ad-hoc names (ask_pipeworx, forget, recall). There is no consistent verb_noun or noun-only pattern across the set, making it hard to predict tool names.
38 tools is excessive for a server named 'Lemmy' where only 7 tools (comments, communities, community, post, posts, search, site) actually relate to Lemmy. The vast majority of tools belong to an unrelated Pipeworx data platform, creating a severe scope mismatch and making the server feel bloated and unfocused.
For the Lemmy domain, the tools cover read-only browsing (list posts, view post, list communities, fetch community, comments, search, site metadata) but completely lack write operations like posting, commenting, voting, or moderation. The Pipeworx tools are extensive but do not compensate for the primary domain's gaps since the server is ostensibly about Lemmy.