opencode_reply

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations, the description carries the full behavioral burden and falls short. It does not say whether the call blocks for a response, whether it is synchronous versus the async sibling, what happens if the session is idle or running, or what the response looks like.

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 front-loaded sentence with no filler is efficient. It is arguably too terse for an 8-parameter tool, but there is no wasted text.

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 an 8-parameter tool with no annotations, no output schema, and 13% schema coverage, one sentence is far too thin. The agent lacks enough context on behavior, return, and parameters to invoke this correctly.

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 only 13% (just the directory param), yet the description mentions none of the parameters. Six parameters (agent, format, modelID, variant, providerID, sessionId) are undocumented in both the schema and the description, so the description fails to 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 clear verb+resource: sending a message to an existing session. However, it does nothing to distinguish opencode_reply from near-identical siblings such as opencode_message_send, opencode_message_send_async, opencode_fire, or opencode_ask, leaving the agent unable to tell which one to pick.

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 indication of when to use this tool versus the many message-sending and session-interaction siblings. 'Follow-up' hints at a continuing session but no prerequisite, exclusion, or alternative is named.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.