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

Annotations already declare readOnlyHint/idempotentHint/non-destructive, so the safety profile is partly covered, and the description usefully adds the donor-side flow (Gift Aid, optional tip, card payment) and that amounts remain the donor's to change. It says nothing about the link's lifecycle, persistence, or expiry, and notably never asserts the write implied by the tool name.

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 efficient sentence with no filler, front-loading the artifact and then the donor experience. It is compact for the amount of behaviour it conveys.

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?

An output schema exists, so return values need no explanation, but for a creation tool the description omits everything an agent would want: whether the link is persisted, shareable, single-use, expiring, or reusable given idempotentHint. Adequate but with clear 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?

The top-level `charities` parameter has 0% schema description coverage, and the description only partially compensates: 'with these charities' confirms the array's role and 'the amounts when given' signals that amount is optional. It adds no detail on the 1–6 item limit or the charity-number format, which the nested schema does cover.

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 the artifact ('a link to Legacy's checkout with these charities') and sketches the donor journey, so the resource is identifiable, but it never states the action of *creating* that link — only the title carries the verb. It also gives no signal distinguishing it from siblings check_charities or quote.

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 when-to-use guidance, no prerequisites, and no routing against the sibling tools. An agent must infer from the name alone when to call this versus quote or check_charities.

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