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

Annotations only mark it non-read-only/open-world/non-idempotent; the description goes far beyond by disclosing billing per bank connection, the confirm-gated dry-run vs execution behavior, per-connection cooldown and per-workspace daily limits, and the exact fallback (last known balances plus next allowed time) when a limit is hit.

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?

Long but dense and front-loaded with the core action, then billing, then the confirm mechanic, then alternatives and limits. Every sentence carries distinct information, though the sentence length makes it slightly heavy to scan.

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 still explains what comes back in both branches (cost/connection preview vs fresh balances, and the limit-exhausted fallback payload). An agent needs nothing more to invoke 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 coverage is 100%, so the baseline is 3, but the description adds real behavioral meaning to confirm (false = nothing called, just a cost preview; true = check runs and fresh balances return) that the schema only states tersely, plus reinforcement of the account/company scoping.

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 states a specific verb and resource ('Asks the bank for balances right now') and explicitly scopes it to connections that support live checks. It distinguishes itself from the sync-based alternatives (get_metric, list_accounts) that provide the same data for free.

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?

Explicit when-to-use ('a live check matters only for "right now" questions'), when-not-to (daily balances already in get_metric/list_accounts at no cost), and names the alternatives. The cost gating via confirm also functions as usage guidance.

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