vaultwarden_icon_internalServe a favicon from the local cache without external fetching. Use it when icon fetching is disabled to return a cached site icon for a given host.
Serve a favicon from local cache without external fetch (used when icon fetching is disabled)
| Name | Required | Description | Default |
|---|---|---|---|
| form | No | ||
| host | Yes | ||
| params | No | ||
| json_body | No |
Changes observed during successful MCP inspections.
v0.2.2Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The description says the tool serves a favicon from local cache without external fetch, implying a read-only, closed operation. This directly contradicts the annotations readOnlyHint=false and openWorldHint=true, so the behavioral picture is inconsistent rather than transparent.
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?
The description is a single tight sentence with the action front-loaded and the usage condition in a parenthetical. It is efficient, though its extreme brevity leaves important details uncovered elsewhere.
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 tool with four undocumented parameters and no output schema, the description is too sparse to fully guide invocation. It explains the tool's purpose but omits parameter roles and contradicts the safety annotations.
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?
The input schema has four parameters (host required, plus form, params, json_body) with 0% schema description coverage, and the description provides no information about any of them. An agent cannot tell what host means or how the other parameters should be used.
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 states a specific verb ('Serve') and resource ('favicon') and scopes it to local cache without external fetch, clearly distinguishing it from the sibling external icon-fetching tool. An agent can immediately understand what this tool does.
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?
The parenthetical 'used when icon fetching is disabled' gives a clear condition for when to use this tool. It does not explicitly name or compare with vaultwarden_icon_external, but the local-cache vs external-fetch distinction is strongly implied.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.