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

Annotations already signal read-only, idempotent, and non-destructive behavior. The description adds meaningful context beyond these, including partial-name relevance scoring, a 50-match per-call cap, full ABR coverage, and source/licensing constraints; no behavioral contradiction is present.

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 front-loaded with the core action, then moves through return fields, matching behavior, filters, and limits. Every sentence carries useful information, though it could be trimmed slightly and still be complete, so it earns a 4 rather than 5.

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 read-only search tool, this is quite complete: it names the source, scope, result cap, filter options, and returned attributes, and an output schema exists. Minor ambiguity remains about how state and postcode filters combine and what happens when no matches are found, but nothing critical is absent.

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 covers 100% of parameters with descriptions, so the baseline applies. The description does reinforce partial name matching and optional filters, but most parameter meaning is already in the schema, so it adds little beyond the structured fields.

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 opens with a specific verb and resource ('Search the Australian Business Register (ABR) by business name to find matching entities') and enumerates the returned fields. This makes it unambiguous and separates it from sibling exact-lookup tools (abr.business.abn_lookup, abr.business.acn_lookup) even though they are not named.

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?

It gives clear search context: partial name matching, optional state/postcode filters, and a 50-result cap. It does not explicitly name alternatives such as abn_lookup for when the ABN is already known, so it misses the when-not guidance needed for a 5.

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