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

The readOnlyHint annotation already establishes this as a safe read operation. The description adds only that it returns one account; it does not disclose not-found behavior, authentication needs, rate limits, or any return-format context beyond the annotation.

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 a single front-loaded sentence with no wasted clauses. It is appropriately sized for a simple lookup, though the sentence-fragment style leaves it slightly under-structured.

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 one-parameter read tool with full schema coverage and a readOnly annotation, the description is sufficient to invoke the tool. However, no output schema exists and the description does not explain returned account fields or behavior when the account number is not found.

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 100%, and the schema already documents the account number parameter with the same 1930 example. The description repeats that example without adding format, range, or validation details beyond the schema.

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 retrieval of one chart-of-accounts account by number, with example 1930. It implicitly distinguishes a single-account lookup from the sibling list_chart_of_accounts by saying 'One account', though it does not name that 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?

No explicit when-to-use, when-not-to-use, or alternative is provided. The phrase 'by its number' implies the tool is appropriate when the account number is known, but the description never directs the agent to list_chart_of_accounts when the number is unknown.

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