AssignToCategory

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

Annotations already declare non-read-only, idempotent, non-destructive behavior, so the bar is lower. The description adds genuinely useful behavioral context beyond them: the delta is drawn from or returned to Ready to Assign, which tells the agent the side effect is a reallocation of the plan's unassigned pool rather than a loss of funds.

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?

Two short sentences, zero filler, with the core action stated first and the funds-flow consequence second. Every sentence earns its place.

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?

An output schema exists, so return values need not be described. For a money-mutation tool, the description supplies the key semantic (Ready to Assign as the counterparty), though it omits any note on permissions or overwrite behavior of the prior assignment.

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 baseline is 3. The description itself adds no parameter-level detail (no mention of month format, plan_id defaulting, or the total-vs-increment distinction), all of which is already handled by the schema.

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?

States a specific verb and resource ('Set how much is assigned to a category for a month'), which is unambiguous. It does not, however, differentiate itself from the sibling Ynab_MoveMoney in the description text itself — that differentiation lives only in the parameter 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 description gives no explicit when-to-use or when-not-to-use guidance; routing to MoveMoney for incremental moves appears in the `amount` schema description rather than the tool description. Usage is only implied by the 'assigned amount for a month' framing.

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