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

No annotations are supplied, so the description carries the full burden, and it does disclose real operational traits: it is free, capped at 20 calls/day per client, informational only ('not legal advice'), and scoped to a single jurisdiction. It does not describe response shape or pagination, but for a free static-information tool that gap is minor.

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 with the question it answers, then the payload, then the scope/limit caveats in roughly priority order. It is dense and slightly list-heavy, but every clause (rate bands, VAT note, source/date, rate cap, disclaimer) adds distinct 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 output schema, the description must convey the return content, and it does enumerate the bands, VAT note, and source/date metadata. The main omission is return format (structured fields vs. prose), but the core informational contract is complete for a zero-param tool.

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?

Zero parameters, so the baseline is 4; the empty object schema means there is nothing further to document. The description correctly implies a parameterless lookup rather than hinting at hidden inputs.

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 the specific resource (Irish residential stamp duty rates) and enumerates exactly what is returned: the rate bands, the VAT note for new builds, plus source and date. It also explicitly distinguishes itself from the sibling paid_purchase_cost, so an agent can route without opening a schema.

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?

Names the condition that selects the alternative ('Does not calculate for a price; the paid purchase-cost tool ($0.01) does'), which is clear routing guidance. It does not spell out a positive 'use this when you need the statutory bands for a lookup' trigger, but the first sentence implies it well enough.

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