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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, so the safety profile is covered. The description adds the price (3¢ per call) and a hint about the output structure (GCCSA + state), which provides some behavioral context beyond annotations. However, it doesn't explain edge cases, failure modes, or the exact return format, so it's only marginally more transparent.

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 very short (one sentence plus price), which is concise. However, the main statement is vague and not front-loaded with the most important information (what the tool does). The price is useful but the core function is unclear, so it doesn't earn its place effectively.

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?

Given the simple tool (one param, no output schema), the description should at least clarify the return value and usage. It mentions the output includes GCCSA and state, but doesn't explain the format or that it's a profile lookup. Without an output schema, the description must cover this, and it falls short. It's incomplete for an agent to use correctly.

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?

With schema description coverage at 0%, the description must compensate for the single parameter sa4_name. It does not explain what sa4_name means, its format (e.g., name vs code), or provide examples. The description only mentions 'SA4' generically, which doesn't clarify the parameter's expected value. This is a significant gap.

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 'SA4's parent chain — GCCSA + state' hints at the resource but lacks a clear verb or explicit statement of what the tool does. It doesn't say 'returns' or 'gets' the parent chain, leaving the action implicit. It does distinguish from some siblings by mentioning the geographic hierarchy, but it's too vague for an agent to know it's a lookup/profile operation.

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?

There is no guidance on when to use this tool versus alternatives like lga_profile, mbs_profile, or suburbs_profile. It doesn't state that it's for SA4-level geography or mention any conditions. The presence of sibling profile tools without any differentiation makes the usage context unclear.

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