get_balance

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

The readOnlyHint annotation already signals a safe read operation. The description adds meaningful behavioral context by disclosing that future-dated transactions, scheduled payments, and accrued interest are excluded by default, and that passing a future as_of_date changes the balance projection. No contradiction with annotations.

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: a one-sentence purpose, a concise behavioral note, then an Args block. Minor redundancy exists ('Defaults to today's date' and later 'Defaults to today'), but overall it is efficient and front-loaded.

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 an output schema present and both parameters well documented, the description covers what an agent needs to invoke the tool correctly. The main gap is that balance computation semantics beyond future-date exclusion are not described, but this is not essential for basic invocation.

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 0%, but the description fully compensates by documenting both parameters: account_name includes acceptable formats (full path, %short GUID, full 32-char GUID) and as_of_date specifies ISO format and default behavior. This adds significant meaning beyond the bare schema field titles.

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: 'Get the balance of an account as of a specific date.' This clearly distinguishes the tool's core function from account metadata tools like get_account or get_book_summary, though it does not explicitly name sibling alternatives.

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 gives clear usage guidance around the date behavior: it defaults to today, excludes future-dated transactions, and instructs when to pass an explicit as_of_date to project forward. It does not explicitly discuss alternative tools or exclusion conditions, but the when-to-use context is strong.

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