List all messages in an OpenCode session with formatted roles and content, optionally limiting results and targeting a project directory.
List all messages in a session with formatted roles and content.
| Name | Required | Description | Default |
|---|---|---|---|
| limit | No | Max messages to return | |
| directory | No | Project directory to target. Optional; defaults to the server default project. | |
| sessionId | Yes |
Changes observed during successful MCP inspections.
v3.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations at all, the description carries the full behavioral burden. It hints that output is 'formatted roles and content' but says nothing about ordering, defaults, truncation, or pagination behavior, and 'all messages' directly conflicts with the 'limit' parameter defined in the schema.
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?
A single well-formed sentence with no filler and a clear front-loaded verb. It is efficient, though the brevity is partly under-specification rather than true economy.
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?
No output schema and no annotations mean the description must explain return shape, ordering, and limits, and it does none of these. For a three-parameter read tool with an ambiguous sibling set, this leaves the agent with too many open questions to invoke it confidently.
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 coverage is 67% — limit and directory are documented in the schema, but sessionId has no description anywhere. The description adds no parameter meaning and actively muddies 'limit' by claiming the tool lists 'all messages', so it does not compensate for the coverage gap.
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 gives a specific verb+resource (list messages in a session) plus a hint at presentation ('formatted roles and content'), which is clearer than the bare name. However, it does not distinguish itself from the sibling opencode_message_get, which an agent would need in order to choose between listing and fetching a single message.
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?
There is no statement of when to use this tool versus opencode_message_get, opencode_session_search, or opencode_session_todo. No prerequisites (e.g., a valid session must exist) are mentioned; the agent must infer the context entirely.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.