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

Annotations already cover the safety profile (readOnlyHint, idempotentHint, destructiveHint=false, openWorldHint=false), so the bar is lower. The description still adds real behavioral value: a 150-word cap, 'unknown' as the fallback for missing facts, linked sources, an appended disclaimer, a 6-hour collection cadence with pre-publish auditing, and the structural guarantees that numbers are {value, unit} and every record carries as_of.

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?

Purpose is front-loaded in the first clause, and the long middle enumeration of report sections earns its place because there is no output schema. The slash-separated run-on writing is dense and harder to parse than it needs to be, which keeps it out of the top score.

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 usefully characterizes the return: section list, word limit, unknown-handling, unit shape, and as_of field. Provenance and freshness are also covered. Minor gaps remain around error behavior for an unrecognized symbol and how slugs resolve against tickers.

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 100% and the single parameter already documents that 'symbol' accepts a slug or ticker with examples. The description adds nothing beyond 'one coin', so the baseline of 3 applies.

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 a specific verb and resource ('Find crypto gems: the short Degen report on one coin') and enumerates the report's sections, so an agent knows it returns a single-coin narrative rather than a ranked list. However, it never names its obvious siblings (gem_screener_coin, gem_screener_picks, gem_screener_ranked), so differentiation is left to inference.

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?

'A research screen, not a signal' and 'Read-only, no key' give some framing for how to treat and call it, and 'on one coin' implies single-symbol scope. But there is no explicit when-to-use vs when-not guidance and no routing to the sibling gem_screener tools for list or ranked views.

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