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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, and the description corroborates rather than contradicts them while adding the business consequence (cash double-counted, P&L inflated) and the return shape. The only redundancy is restating 'Read-only', which the annotations already carry, so it falls just short of the top mark.

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 the core purpose, then the failure mode, then the trigger phrases and the sibling routing. The parenthetical list of seven integrations is long but does establish scope. Slightly dense prose, but essentially every clause carries 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?

With no output schema, the description steps in to define the return value (candidate pairs, matched/unmatched counts, date ranges, sample matched pairs, AI same-account verdict), and the single optional param is fully covered by the schema. Nothing an agent needs to call and interpret this tool is missing.

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?

There is a single optional parameter with 100% schema description coverage, so the schema already explains the company selection and the list_companies fallback. The description adds nothing about the parameter, which is acceptable at this coverage level but not value-adding.

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?

Names a precise verb and resource (find duplicate bank accounts) and defines the exact scenario: a manual account mirroring a connected live feed, causing double-counted cash. It also distinguishes itself from the mutation path by naming merge_bank_accounts as the tool that performs the merge, so an agent can tell the two apart without inspecting schemas.

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 explicit triggering conditions (user says cash/balance looks wrong after connecting a bank, mentions a duplicate account, or asks why P&L looks inflated) and an explicit exclusion/routing note ('Read-only — use merge_bank_accounts to actually merge a pair'). No inference required.

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