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

Annotations only give generic write/non-destructive flags; the description adds real substance by disclosing that it does NOT change the balance value and only removes a warning flag, so the name doesn't mislead. It doesn't address idempotency or failure modes, which is the remaining gap.

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 action, then supporting context, then Args/Returns. The docstring-style Args/Returns blocks add slight overhead, but the Returns note is justified given no output schema exists.

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 1-param tool with no output schema, the description covers scope, behavioral effect, and the return value ('Updated account snapshot'). Minor omissions like behavior on non-Plaid accounts and idempotency keep it from a 5.

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 0%, so the description must carry the load — and it adds meaningful constraint by defining account_id as 'The Plaid-linked account', not just any account. It lacks format/type detail (integer ID), but compensates for the coverage gap reasonably well.

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+resource — accepting Plaid's reported balance as correct and clearing the mismatch warning — and explicitly distinguishes itself from the sibling override_account_balance ('unlike a balance override'). An agent can tell exactly what this does and how it differs from the value-changing alternative.

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?

Clearly scopes applicability ('Plaid-linked accounts only') and contrasts with the balance-override alternative, implying when to use each. It stops short of an explicit when-not-to-use statement or error handling for non-Plaid accounts, but the routing intent is clear.

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