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

No annotations exist, so the description carries the full behavioral burden and does essentially none of it — nothing about matching behavior (exact vs fuzzy), whether the upstream register is rate-limited or requires a key, or how results are ranked. The only behavioral signal, includeHistorical, is documented in the schema rather than the description.

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?

A single front-loaded sentence with zero waste. The brevity edges into under-specification, which is penalized under contextual completeness rather than here, but it stops just short of a 5 because there is no second sentence of routing value.

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?

With no annotations and no output schema, the description is the only place an agent can learn behavior, and it says nothing about what comes back (name, ABN, status, address) or how to handle zero/many matches. For a 4-parameter public-register search, a one-line description leaves material gaps.

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% — q, limit, state, and includeHistorical are all documented in the schema, so the baseline is 3. The description adds no guidance on query syntax (partial names, ABN prefixes, punctuation) or on how state and includeHistorical interact with the search.

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 (search) and resource (ABNs) with the key constraint that matching is by business name rather than by number. It does not, however, mention or distinguish itself from the sibling abn_lookup, so the agent must infer that lookup handles number-based retrieval.

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 only implied: because the query is a business name, an agent can infer this is the entry point when it doesn't already have an ABN. There is no explicit when-to-use, no statement of when to prefer abn_lookup, and no prerequisite or fallback guidance.

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