datailo_invokeCall one tool of an enabled service through the hub: service, tool name and its arguments (see datailo_tool_schema). Returns the service's own result.
| Name | Required | Description | Default |
|---|---|---|---|
| args | No | ||
| tool | Yes | ||
| service | Yes | ||
| session | No | The `session` value datailo_connect_verify returned. Pass it on every Datailo call in this conversation; omit it when the user connected with Sign in (OAuth) or a key. |
Changes observed during successful MCP inspections.
Input schema / properties / session / descriptionPrevious value: -"The `session` value datailo_connect_verify returned, when this client keeps no connection session. Pass it on every Datailo call in this conversation; omit it when the user connected with Sign in (OAuth) or a key."New value: +"The `session` value datailo_connect_verify returned. Pass it on every Datailo call in this conversation; omit it when the user connected with Sign in (OAuth) or a key."Input schema / properties / sessionAdded value: +{
+ "anyOf": [
+ {
+ "type": "string"
+ },
+ {
+ "type": "null"
+ }
+ ],
+ "default": null,
+ "description": "The `session` value datailo_connect_verify returned, when this client keeps no connection session. Pass it on every Datailo call in this conversation; omit it when the user connected with Sign in (OAuth) or a key.",
+ "title": "Session"
+}Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations include readOnlyHint=false, which aligns with the description's 'Call' implying mutation/action, and openWorldHint=true, indicating dynamic behavior. The description adds the return value ('Returns the service's own result') and references datailo_tool_schema for args, but does not disclose side effects, error handling, or rate limits, which would be valuable for an invoke tool.
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 one sentence, concise, and front-loads the core functionality. It avoids redundancy with the annotations. It could be improved by adding a second sentence on when to use it, but it is efficient and informative.
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?
Given the tool's complexity (dynamic invocation, 4 params, no output schema), the description covers the basic purpose and links to datailo_tool_schema, but lacks guidance on error handling, side effects, and prerequisites like enabled service or connection. The annotations provide limited context, so the description should carry more weight but does not fully address these gaps.
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 description coverage is low (25%), with only the 'session' parameter described in the schema. The description adds meaning by indicating that 'service', 'tool', and 'args' are required, but it could provide more detail on the expected format of 'args' and clarify that 'service' and 'tool' correspond to entries from datailo_tool_schema. Despite this, it does compensate partially for the low schema coverage.
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 ('Call') and resource (a tool of an enabled service via the hub), and mentions it requires service, tool name, and arguments. It distinguishes itself from siblings like datailo_tool_schema, but does not explicitly contrast with datailo_describe or datailo_tools, which may also relate to tool information, though those are likely read-only.
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 description implies it is the action tool for invoking tools, while siblings like datailo_tool_schema or datailo_describe are for inspection. However, it does not explicitly state when to use this tool versus alternatives, nor does it mention prerequisites like needing an enabled service or prior connection.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
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