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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, open-world), yet the description still adds real behavioral detail: schools are matched by postcode text, deduplicated by school code, unranked by distance, and may include closed campuses. It also discloses the response form (English natural-language text, sources and conditions preserved, pagination present) and a scope limit on the classification.

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?

Three sentences, front-loaded with the core purpose, then deduplication semantics, then response format. Every sentence carries usable information, though the density makes it slightly heavy for a two-parameter lookup.

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 output schema, the description carries the return-value burden and does so reasonably well (content type, deduplication, pagination, caveats). Minor gaps remain: it never states what the 'Category 2/Category 3' values mean or whether results can be empty for a valid postcode.

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 both parameters (postcode pattern, locale enum with default) are fully documented in the schema. The description adds no syntax, format, or default information beyond that, so the baseline 3 applies.

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 and resource (get localities/state, regional category, and schools for one Australian postcode) with explicit scope. It is clearly distinguishable from the bulk search sibling by its single-postcode scope, but it never names an alternative tool, so it falls short of full sibling differentiation.

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: the tool is a per-postcode lookup, and the schema (not the description) tells the agent to feed it a postcode from search_postcodes. The description offers interpretation caveats (not distance-ranked, may include closed campuses, classification is not visa eligibility) but no explicit when-to-use or when-to-prefer-another-tool guidance.

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