Set the entry, do, or exit action of a state by specifying its ID, action kind, and body content.
Set an entry, do, or exit action body on a State. action_kind must be 'entry', 'do', or 'exit'.
| Name | Required | Description | Default |
|---|---|---|---|
| body | Yes | ||
| state_id | Yes | ||
| action_kind | Yes |
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
Changes observed during successful MCP inspections.
v0.1.1Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full burden of behavioral disclosure. It reveals that the tool mutates a State action body and constrains action_kind, but it does not disclose overwrite behavior, required State existence, permissions, side effects, or return values.
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 compact two-sentence definition with no filler. The first sentence states the action and target, and the second adds the critical action_kind constraint with no redundancy.
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 setter with three required string parameters and an output schema, the description provides a minimally viable invocation context. It is incomplete in that it lacks explicit usage boundaries, prerequisites, or side-effect warnings, but the tool's low complexity and clear parameter intent keep it from being significantly deficient.
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 0%, so the description must compensate. It usefully defines action_kind as 'entry', 'do', or 'exit' and implies body is the action body, but state_id semantics are only implicit through the tool name and the phrase 'on a State'. Body format and state_id resolution are not clarified.
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 uses a specific verb ('Set') and identifies an unambiguous resource: an entry, do, or exit action body on a State. It clearly distinguishes from transition-related tools like set_transition_trigger or set_transition_effect by narrowing scope to State actions and enumerating the allowed action_kind values.
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 phrase 'on a State' gives implied context for when this tool should be used, and action_kind values reinforce that. However, it does not explicitly state when not to use it or name alternatives, leaving the agent to infer the selection criteria.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.