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

Annotations already declare this is a non-readonly, non-idempotent, non-destructive write operation, and the description adds meaningful behavior: version auto-incrementation for plans with the same name and year. The forecast convention also explains a critical correctness requirement beyond the annotations. It does not cover permissions, failure modes, or return values, but it is well beyond baseline transparency.

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 the core action, then adds the auto-increment behavior, then the forecast convention. Every sentence carries operational value, and there is no filler or 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 create tool with no output schema, the description covers the critical forecast workflow and versioning behavior well. It does not explain what the tool returns after creation, such as a plan ID or version, but annotations and the schema already cover safety and parameter details.

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 100%, so the schema already documents all four parameters. The description adds important semantic meaning for the type parameter by defining the required forecast convention when type=forecast, which is not derivable from the enum alone. It does not elaborate on budget or scenario types, but the key parameter constraint is covered.

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 verb and resource: "Create a new budget plan." It also implicitly distinguishes plan creation from entry loading by directing the agent to upload-budget-entries for category entries. An agent can identify this as the plan-creation tool without opening the schema.

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 forecast convention gives clear, actionable guidance for when type=forecast: read actuals from get_periodic_summaries/category_totals and load them with the forecast via upload-budget-entries. It does not explicitly state when not to use this tool or compare it against list_budget_plans, but the workflow context is strong.

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