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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds valuable behavioral context: the ranking is weighted by engagement over the window, and it clarifies that a topic posted about loudly by few accounts does not outrank one discussed widely. This goes beyond the annotations.

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 compact and front-loaded: the first sentence states the core purpose, the second explains the ranking methodology, and the third routes to the alternative. Every sentence earns its place with no wasted words.

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 simple read-only tool with 2 optional parameters and no output schema, the description is nearly complete. It explains what the tool returns (ranked topics), how ranking works, and when to use it. The only minor gap is not explicitly describing the output format, but since there is no output schema, a brief note on return shape would help. Still, the description is strong enough for an agent to call it correctly.

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 0%, so the description carries the burden for parameter meaning. However, the description does not explain the 'hours' or 'limit' parameters beyond what the schema shows (integer, default values). The description's mention of 'over the window' implies hours controls the time window, but it doesn't explicitly map parameters to their semantics. Baseline 3 is appropriate since the schema provides names and defaults but no descriptions.

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 uses a specific verb ('Rank') and resource ('what the market is TALKING ABOUT — themes and narratives, not assets'), and explicitly distinguishes itself from get_trending_assets. It clearly states the tool's scope and what it is not, making it easy for an agent to differentiate from siblings.

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 explicitly says 'Use get_trending_assets for tickers; this is the layer above' — providing a direct alternative and the condition for choosing this tool. It also explains the ranking methodology (mentions weighted by engagement) which helps the agent understand when this tool is appropriate.

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