Money movements — List

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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description goes well beyond that by disclosing null-semantics for from/to_category_id (Ready to Assign), the milliunits unit convention, and the stateful sync contract of last_knowledge_of_server — real behavioral context an agent needs to interpret results.

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?

Front-loaded with purpose and concept definition before the sync mechanics, and every sentence carries information. The final changes_since sentence is slightly tangential for a listing tool, but it is one sentence and it does route the agent correctly.

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; instead the description covers the domain concept, unit interpretation, null handling, and sync semantics. For a 2-parameter, zero-required, read-only list tool, that is everything an agent needs to call 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 description coverage is 0% and the schema only supplies titles, so the description must carry the load. It does: last_knowledge_of_server is explained as the server_knowledge value from an earlier response, and plan_id is contextualized as the plan being listed. This is meaningful added semantics, though it doesn't state plan_id's type/format or what happens when it is omitted.

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 ('List all money movements for a plan') and then defines the domain concept precisely: budgeted funds moved between categories within a month, explicitly not a transaction with no payee or account. That definition cleanly separates it from the many transactions_* and money_movement_groups_* siblings.

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?

Gives concrete when-to-use guidance for delta sync ('pass last_knowledge_of_server ... and YNAB sends only what changed'), which selects this tool for incremental refresh. It also names the alternative changes_since for cross-resource sync. It stops short of stating when to prefer money_movements_list_by_month or money_movement_groups_list, so it is clear context rather than full routing.

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