Consolidate / Rename a Payee

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

Annotations indicate idempotentHint=true and destructiveHint=false. The description adds valuable behavioral context beyond annotations: step-by-step how it works (finds transactions, renames payee, links transactions) and the behavior when target_name already exists. It also emphasizes the preview step, which is critical for safe usage.

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 well-structured: starts with a clear one-sentence purpose, provides bullet examples, an important warning, a numbered how-it-works list, and a final note. It is concise despite moderate length, with each section contributing necessary information.

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?

Given the tool's complexity (renaming a payee with transaction updates), the description covers purpose, usage guidelines, preview requirement, internal behavior, and a note about YNAB's API limitations. It also references sibling tools for IDs. An output schema exists, so return values are not needed. The description is sufficient for an agent to use 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?

Input schema has 100% coverage with property descriptions explaining each parameter (e.g., preview_only default true). The description does not provide additional parameter-level semantics beyond what the schema offers, but the overall workflow context (preview first) is already embedded in the schema. Baseline of 3 is appropriate.

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 clearly states the tool's purpose: renaming a payee and updating all its transactions to a canonical name. It provides concrete examples (e.g., 'AMZN*1A2B3C4D' → 'Amazon') and distinguishes itself from sibling tools like updatePayee or createPayee by describing the consolidation/merging behavior.

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 explicitly instructs to always call with preview_only=true first, explains when to set it to false only after reviewing, and provides context on when to use this tool (cleaning up messy payee names). It also explains that YNAB lacks a delete payee endpoint, making renaming the correct approach for deduplication.

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