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

Annotations already declare readOnly, idempotent, non-destructive and open-world behavior, so the safety profile is covered. The description adds meaningful non-schema context: the content is delayed, from the previous edition, and omits OI, sentiment and markdown formatting — real limitations an agent needs to know. It does not address freshness lag magnitude or rate limits, so it is strong rather than exhaustive.

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 dense sentence: the free/tier framing leads, limitations follow in parentheses, and the routing instruction closes. Every clause carries information and nothing is padding.

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 does the work of characterizing the returned payload (a trimmed, delayed brief lacking OI/sentiment/markdown), which is sufficient for an agent to call it correctly. Missing only peripheral details like delay duration or refresh timing.

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?

There are zero parameters, so per the baseline rule this scores 4. The description correctly implies a no-argument call by not describing any 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?

The description names a specific resource (a delayed, trimmed sample of the twice-daily crypto brief) and explicitly distinguishes it from the sibling it is not: get_latest_brief. An agent can tell exactly what this returns and how it differs from paid siblings without opening any 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?

It gives a clear selection condition — 'Use to evaluate before paying for get_latest_brief' — which routes the agent between the two tools. It does not mention other plausible alternatives such as get_teaser or when this tool is the wrong choice, so it stops short of a full when/when-not statement.

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