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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds one genuinely new constraint — "Paid plans only" — which is plan-gating context an agent would otherwise miss, but it says nothing about what happens on an invalid or inaccessible setId.

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?

Two short sentences with the action first and the plan restriction second; nothing is padded or repeated from the name or annotations.

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 single-parameter read tool with full annotation coverage, the definition covers what it returns at a high level (criteria) and the plan gate. Only the failure/inaccessible-set case and any auth prerequisites are left unstated, which is a minor gap.

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 setId parameter already documents that the id comes from listSignalSets, so the schema carries the parameter burden. The description adds no further meaning such as format, range, or behavior for unknown IDs; baseline 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?

States a specific verb and resource ("Get one of your signal sets") and notes the payload includes its criteria, which distinguishes it from listSignalSets by scoping to a single set. It stops short of explicitly naming the listing sibling as the way to discover IDs, so it is clear but not fully differentiated in the text itself.

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 singular "one of your signal sets" implies retrieval after a listing call, and the setId schema description reinforces this by pointing at listSignalSets. There is no explicit when-to-use/when-not guidance and no mention of previewSignalSet as an alternative for inspecting criteria before saving.

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