opencode_job_cancel

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

No annotations are provided, so the description carries the full behavioral burden. 'Abort' implies a terminating mutation, but the description never states reversibility, required permissions, effect on in-flight work, or error/not-found behavior, which matters for a cancel operation.

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 short, front-loaded sentence with no padding, which is structurally fine. It is terse to the point of under-specification rather than wastefully verbose, so it avoids penalty but earns no praise.

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?

With no annotations, no output schema, partial parameter coverage, and a crowded sibling namespace, the description is too thin. It does not disclose the outcome of the abort or how it differs from the many session-permission and abort-adjacent siblings.

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 only 50% ('sessionId' is undocumented) and the description adds no parameter meaning at all. 'Session owned by a task' hints at a session identifier, but neither the schema nor the description explains how sessionId relates to the 'task' framing or what directory does.

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 ('Abort') and a scoped resource ('the OpenCode session owned by a task'), which is more than a tautology. However, the tool is named 'job_cancel' yet describes aborting a session, and a sibling 'opencode_session_abort' exists, leaving the boundary between the two unclear. An agent cannot confidently tell this apart from the sibling from the description alone.

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?

No when-to-use guidance, no prerequisites, and no mention of alternatives such as opencode_session_abort or opencode_job_get. The agent is left to infer when cancellation is appropriate versus stopping a session directly.

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