start_planning

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

No annotations are provided, and the description only states the action without disclosing behavioral traits such as whether it overwrites an existing session, requires a prerequisite, or has side effects. This leaves the agent without critical safety/state information.

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 single, front-loaded sentence with no filler. Every word contributes to conveying the tool's purpose, making it highly concise and well-structured.

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 session-initiating tool, the description lacks important context about what happens to an existing session, whether the operation is destructive, and how it relates to sibling tools like get_plan or save_plan. The absence of annotations makes this gap more significant.

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?

The input schema already provides 100% coverage for the single parameter 'goal' with a clear description. The tool description adds no additional semantic detail beyond mentioning 'goal', so the baseline score of 3 applies.

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 'Start a new planning session with a goal' uses a specific verb ('start') and resource ('planning session'), and clearly distinguishes from sibling tools like save_plan or update_goal, which imply saving or modifying rather than initiating.

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 'new planning session' implies usage when beginning a fresh session, but it does not explicitly state when to use versus alternatives or mention exclusions. There is no guidance about using update_goal for existing sessions.

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