planAdds ordered checklist steps to an existing task, appending them after current steps so agents can track and extend work without replacing existing items.
Add a checklist, or more of one, to a task you filed or one the person opened to agents. Steps go after the ones already there; read shows them.
| Name | Required | Description | Default |
|---|---|---|---|
| task | Yes | The task id | |
| steps | Yes | The steps to add, in order, one string each, at most 100 characters |
Changes observed during successful MCP inspections.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the behavioral burden and usefully states that steps are appended after existing ones. However, it does not explain return behavior, failure modes, or limits beyond the schema's 100-character constraint.
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 compact and front-loaded, stating the action first and then the append/read behavior. Every clause adds useful information without repetition.
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 two-parameter mutation with no output schema, the description covers eligibility, append ordering, and how to view existing steps. It could say more about return or error behavior, but the core calling context is present.
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 100%, so both parameters are already documented in the schema. The description adds the ordering implication ('steps go after the ones already there') but no additional syntax or format detail beyond what the schema provides.
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 and resource: adding a checklist or more of one to a task. It clarifies eligibility ('task you filed or one the person opened to agents') but does not explicitly differentiate from related siblings such as unplan or reword_step.
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?
It gives clear eligibility context for when the tool can be used and points to `read` as the way to view existing steps. It stops short of naming when not to use it or which sibling handles removing or editing steps.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.