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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety is covered and the description instead spends its words on what each ranking actually measures ('biggest 24h floor gains with real volume', 'most real volume over 7 days') — genuinely useful context the enum alone lacks. It does not disclose result count, pagination, or how ties/ordering are resolved, which keeps it below 5.

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?

Front-loaded with the resource and its ranking nature, then definitions in parentheticals, then the scoping constraint last. Two sentences, no filler, no restatement of the tool title.

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 two-parameter read-only tool with no output schema, the description covers the semantics of both inputs and the nature of the result ('ranked lists'). What it omits is the shape of the return — how many collections come back and whether the ranking is paginated or capped — which an agent would want before calling.

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 50%: the chain parameter is documented inline, but the list enum is bare in the schema. The description compensates by defining all four enum values, which is precisely the missing half. It also adds the cardinality constraint ('optionally one network') that the schema type alone (a plain string) does not convey.

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?

States a concrete resource ('ranked lists of collections') and then enumerates the four ranking modes with a one-clause definition of each metric (e.g. 'trending = today's volume against its usual day'). An agent can distinguish this from find_collections or collection without opening the schema, and the optional network scope is named up front.

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 implicitly tells the agent when each list value applies, but never says when to use this tool instead of find_collections or collection, nor when not to use it. Usage is inferable from the list definitions rather than being stated.

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