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

Annotations already establish read-only, idempotent, non-destructive behavior, and the description adds useful semantics: balances are as of as_of (default today), and income/expense accounts cover fiscal year to date. It also notes the tool is free, but it omits any explanation of include_archived behavior.

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 three short sentences, front-loaded with the main purpose and followed by the important balance-scope distinction. Every sentence adds value with no repetition or filler.

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 simple read-only listing tool with annotation coverage and no output schema, the description covers the returned fields, date semantics, balance interpretation, default date, and cost. The main remaining gap is that include_archived is left unexplained.

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?

With 50% schema description coverage, the description meaningfully enriches as_of by adding the default-today rule and balance-date semantics. However, include_archived is not explained in either the schema description or the tool description, leaving one of the two parameters ambiguous.

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 clearly identifies the resource (every account) and the fields returned (code, type, role, balance), which makes the listing purpose obvious. It does not explicitly distinguish itself from nearby tools such as account_balance or books_get, so it falls short of a 5.

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?

Usage is implied by the phrase 'Every account' and the balance-scope details, but there is no explicit when-to-use or when-not-to-use guidance relative to account_balance or books_get. It is adequate but leaves the agent to infer the selection context.

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