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

Annotations already cover readOnly/idempotent/non-destructive, but the description adds genuinely new behavior: the not-metered property and, importantly, that an unknown chart_id is an error instead of a silent widening. It also explains what 'total' means (signed sum of unvoided journal lines), which is useful behavioral context.

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 and scope, and every sentence carries information. The long enumeration of row fields is the weakest part, since an output schema exists and already conveys those names.

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 three-parameter read tool with full schema coverage and an output schema, this is essentially complete: scope, error behavior, defaults, and cost profile are all covered. The row-field enumeration is redundant given the output schema, so it falls just short of full marks.

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% and the parameters already document defaults and the chart_not_found behavior, so the description largely restates the schema. It does clarify that chart_id may be active or retired only in the schema, not the description. Baseline 3 is right.

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 and resource ('Lists chart accounts with their current balances') plus the scoping rule for chart_id. It does not explicitly distinguish itself from near-siblings such as list_charts or list_workspace_accounts, so an agent must infer the boundary from names alone.

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 clear operating context: pass chart_id for one chart, omit it for every active chart, and an unknown chart_id yields chart_not_found rather than an empty or widened result. No explicit alternative tool is named for the 'I want flat accounts, not chart rows' case.

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