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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint. The description adds valuable context: it is a 'self-aggregating signal — derived from CF analytics-engine, no PII, just (pack, tool, count)' and is 'cached 5min-1h depending on window.' This goes beyond annotations by disclosing data provenance, privacy, and caching behavior.

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 well-structured and concise. It front-loads the core purpose, then lists three specific use cases, followed by a brief note on data source and caching. Every sentence adds value and the bullet-point format improves readability.

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 tool with a single optional parameter and no output schema, the description covers the key aspects: what it returns, the available windows, the source of the data, privacy implications, and caching. It does not describe the exact response format, but the absence of an output schema makes this a minor gap. Overall, it is sufficiently complete for an agent to decide whether and when to use it.

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 schema already fully describes the window parameter with enum values and a detailed note comparing shorter vs longer windows. The description only restates the window options without adding new semantic information. With 100% schema coverage, 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 states the tool's function: 'Returns the top tools, top packs, and total call volume over a recent window.' It uses the specific verb 'Returns' and names the concrete resources. It also distinguishes itself from sibling tools like discover_tools by emphasizing it is an aggregated signal of other AI agents' calls, not a general discovery tool.

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 explicit 'Useful for' scenarios: discovering hot data sources, confirming canonical tools, and aligning use cases with agent demand. However, it does not mention when NOT to use this tool or explicitly name alternative tools, so it falls short of a 5.

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