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

With no annotations, the description fully discloses key behaviors: refresh cadence ('Refreshed every 5 min'), cost ('Free tier. No payment required.'), and data processing ('Returns wash-filtered data using the same v2.0 algorithm as the paid endpoints'). This goes well beyond basic operation and explains important characteristics.

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 a single sentence that front-loads the primary purpose and then efficiently enumerates the exact contents. Every phrase adds value, with no fluff or redundancy. It is concise despite the number of metrics listed.

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?

Despite zero parameters and an output schema that covers return structure, the description fully contextualizes the tool by specifying time window, refresh rate, pricing, and filtering methodology. It is complete for a zero-input snapshot tool, leaving no operational 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 input schema has zero parameters, so there is nothing to explain. The baseline for 0 params is 4, and the description adds no parameter semantics because none exist. It correctly implies no input is required.

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 states the tool's purpose: 'Get the last-24-hour trends snapshot' with a specific list of metrics (new services count, transaction count, USDC volume, etc.). It distinctly differentiates from siblings by focusing on aggregated trends rather than individual service lookup or search.

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 provides clear context for when to use the tool—when a snapshot of trends over the last 24 hours is needed, refreshed every 5 minutes. It does not explicitly name alternatives or exclusions, but the scope is unmistakable and no alternative tool is implied.

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