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

Beyond annotations, the description discloses that the call is free, explains the returned plan structure, links planned steps to run_tool via trace_id, and specifies a $0.50 cost notification rule. It does not cover error behavior or auth, but it is substantially more informative than the annotations alone.

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 front-loaded with cost and purpose, then returns, workflow, and the cost-notification rule. Every sentence adds useful operational detail with no filler.

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 one-parameter planner with no output schema, the description fully explains what the tool returns, how to use the result, and when to surface cost to the user. An agent has enough information to select and invoke it 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 coverage is 100%, so the schema already documents the sole goal parameter. The description adds a concrete example of an accepted multi-part goal, which meaningfully illustrates the parameter's expected semantics beyond the generic schema text.

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 states a specific resource (a goal) and returns (steps, tool per step, example input, per-step and total cost, and an existing recipe when available). It distinguishes this planning tool from execution by explicitly saying to call it before multi-step work and then use run_tool.

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 explicit usage conditions: call it before multi-step work, then run_tool each step with trace_id = plan_id. It also handles the recipe case and adds a concrete cost threshold requiring user notification before execution.

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