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

Annotations already declare readOnly, idempotent, non-destructive, closed-world, so safety is covered. The description adds substantive behavior the annotations cannot: the two-window (30d vs prior 30d) comparison, that each word carries its biggest game, and that supplying a word narrows output to a single term.

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?

Two sentences, front-loaded with what the tool returns and then how the optional parameter changes behavior. Dense but every clause carries information; the sentence structure is somewhat run-on but not padded.

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 carries the return-value burden and does so adequately: words, comparative counts across two windows, and a representative game per word. Combined with read-only annotations and complete schema coverage, an agent has enough to call and interpret it; only the exact response shape and default limit behavior are unstated.

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 coverage is 100%, so `word` and `limit` are already documented and the baseline is 3. The description goes beyond that by explaining the semantic effect of `word` (single-word lookup rather than the top list) and giving example values, which clarifies intent rather than just syntax. `limit` is left entirely to the schema.

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 precisely what is returned: words appearing in new game names, counted over the last 30 days versus the prior 30, plus the biggest game per word. That is a specific resource and scope an agent can act on. It stops short of explicitly naming sibling tools (rising, top, search) it might be confused with, so it is clear but not sibling-differentiated.

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 concrete decision rule: with a word, you get that word only, and the stated purpose is 'check whether an idea has been done and how it's doing.' That is a real when-to-use scenario with examples (horror, brainrot). No alternatives or exclusions are named, so routing versus `rising` or `top` is left to inference.

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