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

Annotations already mark this as read-only, idempotent, and non-destructive. The description adds valuable behavioral context beyond that: saved sites are per-account, a keyless call returns auth_required rather than an empty list, and the response includes live deltas, alert status, and portfolio flags. This meaningfully informs the agent about failure modes and output dynamics.

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 front-loaded with the most critical prerequisite (key requirement), then moves through use case, parameters, return fields, and exclusions in a logical order. It is a dense single paragraph and repeats some schema-covered parameter details, so it is not maximally concise, but every major section earns its place.

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?

For a read-only tool with full schema coverage, a rich output schema, and strong annotations, the description is nearly complete: it covers auth prereqs, failure behavior, return value highlights, and routing away from sibling tools. The main gap is not addressing the overlapping sibling get_shortlist, which could cause selection ambiguity.

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 the schema already explains the `since` parameter fully, including valid values ('24h'/'7d'/ISO), the default, and the generated_at caching hint. The description largely repeats this information rather than adding new semantic detail, so the baseline of 3 is appropriate.

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 clearly identifies the tool as listing saved sites with a specific in-chat read-back purpose and gives example user queries. It explicitly says what NOT to use it for (save_site, export_dataset), but it does not differentiate from the similarly named sibling get_shortlist, which likely overlaps in purpose.

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?

The description gives explicit when-to-use guidance: 'Use when a user asks to see or review their saved DC Hub shortlist in-chat, or wants to know what moved on it.' It also provides a key prerequisite (call claim_free_key first) and names alternatives for excluded use cases (save_site for adding, export_dataset for file download).

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