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

With no annotations provided, the description carries the full behavioral burden and does disclose an important limitation: it does not confirm that the ABN is registered or active. This prevents the agent from over-trusting results. It does not describe return behavior or side effects, but the validation action is inherently read-only and the boundary statement is the most critical behavioral trait.

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?

Two sentences with no wasted words: the first states the core action and target, the second adds a crucial caveat. Information is front-loaded and every sentence 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 single-parameter validation tool with no output schema and no annotations, the description is nearly complete: it defines scope, accepted input behavior, and key limitations. It omits an explicit return-type description, but the tool name and purpose make a boolean/validation result strongly inferable, so this is a minor gap.

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?

The input schema already documents the abn parameter fully, including that spaces and hyphens are accepted. The description adds only the 'checksum' concept, which is behavior rather than parameter detail, so it does not meaningfully go beyond the schema-covered parameter semantics.

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 ('Validate') and precise resource ('format and checksum of an ABN'), making the tool's function immediately clear. It also distinguishes itself from the sibling validate_acn by targeting ABN rather than ACN, and explicitly clarifies what it does not do (confirm registration/active status).

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 usage context: use for syntactic/checksum validation of an ABN, not for legal or registration status verification. However, it never explicitly names when to use this tool over validate_acn or states selection criteria between the two siblings, so the guidance is only implicit.

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