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

Annotations already cover the safety profile (readOnlyHint, idempotentHint, destructiveHint=false, openWorldHint), so the bar is lower. The description adds real value beyond them: the provenance ('current visa pricing' official table), the currency (AUD), the output surface (English natural-language text preserving sources and conditions), and the existence of pagination.

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?

Front-loaded: the fee components an agent needs to know are in the opening sentence, followed by source/currency and then return-format notes. It is dense and slightly run-on, but every clause (stream list, AUD, plain-text output, pagination) carries information rather than filler.

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 correctly carries the burden of describing the return shape: it enumerates the fee components returned, states the format is natural-language English text, the source, the currency, and that pagination applies. It stops short of covering failure modes (invalid or non-existent subclass) or data-freshness caveats, but is otherwise sufficient to call the tool 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?

Schema description coverage is 100%, so the schema already explains both `locale` (enum + default + URL-prefix effect) and `visaSubclass` (pattern, accepted forms, '491F' normalisation). The description adds nothing per-parameter, so the baseline of 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?

The description names a very specific resource — Department of Home Affairs visa application charges for one visa subclass, broken into stream-level components (main applicant, additional applicant 18+/under 18, non-internet charge, second instalment, STAC) — which leaves no ambiguity about what is returned. It never explicitly names or contrasts a sibling (e.g. get_visa_processing_times or get_agent_pricing), so differentiation is inferential rather than stated.

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 implied by the resource name and the note that it is a public endpoint, so an agent can reasonably tell this is a read-only fee lookup. However, there is no explicit when-to-use guidance, no statement of preconditions (e.g. subclass must exist), and no pointer to the sibling tools an agent might confuse this with.

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