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

Annotations already declare readOnly, idempotent, and non-destructive, so the safety profile is covered. The description adds that results are limited to 'active' accounts, which is a meaningful filtering behavior not present in the 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?

One sentence that front-loads the verb and resource and states the purpose without filler. Every clause earns its place.

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 lookup with two required reference parameters and one optional search, the description plus schema is sufficient to invoke correctly. It names the key output (accountNumber) even though there is no output schema. Minor gaps like result count or pagination are non-essential for such a basic list tool.

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 covers 100% of parameters with descriptions, so the description need only add marginal value. It does restate that search filters by name or number, matching the schema, but adds no new parameter-level semantics. Baseline 3 is appropriate.

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 ('Find') and resource ('active ledger accounts'), and explains the operational outcome: retrieving the accountNumber needed for assignment to an accounting entry line. This clearly separates it from sibling tools like list_accounting_rules, which concern rules rather than accounts.

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 implies the tool should be used when preparing to assign a ledger account to an accounting entry line, since it returns the accountNumber required for that task. It does not name alternative tools or explicit exclusions, but the context is clear.

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