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

Annotations already declare the safe read-only profile, but the description adds real behavioral substance: the five-day/same-amount-and-direction matching heuristic, that it also counts booked and pending transactions, and the default window. 'Read-only' merely repeats the annotation, so this is strong but not maximally informative.

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 comparison, then supporting detail. Slightly run-on, and the trailing 'Read-only' partially duplicates annotations, but nearly every clause 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?

For a multi-source comparison tool with no output schema, the description explains what is returned (unmatched bank transactions plus booked/pending counts) and the default scope. It lacks guidance on empty/edge results or the required bank-feed connection, but is otherwise sufficient to invoke 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 100%, so from/to/account/company are fully documented there. The description restates the 60-day default (consistent with the schema) but adds no new syntax or format detail, so the baseline 3 applies.

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 operation: comparing each connected bank account's posted transactions against the mapped ledger and listing the ones with no matching line. The matching rule ('same amount and direction within five days') makes the intent unambiguous and distinct from a plain transaction listing.

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?

Implies a reconciliation use case ('often waiting in QuickBooks' bank feed to be accepted') and notes the 60-day default, but never states when to reach for this over siblings like list_bank_transactions or find_expenses_without_attachments, nor any preconditions such as needing a connected bank feed.

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