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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so safety is covered. The description adds scope worth knowing -- it covers both Elite and Free tiers and explicitly includes what SwiftPrism does *not* do -- but it says nothing about the return shape or whether the content is static marketing copy versus live entitlement data.

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?

It is a single sentence, which is efficient, but it spends most of its length enumerating feature names ('studio Headline Voice, Market Momentum, Deep Insights, Economic Calendar, holdings, reading languages') that are really payload detail an agent will see in the response. The genuinely useful clause -- that it also describes what the product does not do -- is tacked on at the end rather than front-loaded.

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 zero-parameter, read-only informational tool with no output schema, the description is nearly complete: tier coverage, topic coverage, and the negative scope are all conveyed. What is missing is only a hint about the form of the result, which is a minor omission at this complexity level.

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 tool takes zero parameters, so there is nothing for the description to disambiguate; the baseline for a parameterless tool applies. No misleading or missing parameter information exists.

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 states the resource clearly: a feature-inclusion summary covering 'real-time US stock and world economic headlines, studio Headline Voice, Market Momentum, Deep Insights, Economic Calendar, holdings, reading languages.' It is distinguishable from get_plans and get_languages, but it lacks an explicit verb and never names those siblings, so an agent must infer it is an informational read rather than a pricing or locale lookup.

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 mention of alternatives such as get_plans or start_trial. The agent gets content topics but no condition telling it when this tool is the right call over its four siblings.

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