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

Annotations already declare read-only, idempotent, non-destructive, open-world behavior, so the safety profile is covered. The description adds a genuine data-quality caveat ('Observations can be stale') that annotations cannot express, which is exactly the kind of context that helps an agent hedge its answer.

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?

Three tight sentences, each earning its place: what it returns, when to use it, the alternative, and the freshness caveat. The scope is front-loaded before the sibling routing advice.

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 zero-param, no-output-schema read tool, this covers endpoint, purpose, routing and data freshness. The only thin spot is the shape of the returned market rows, but with no output schema and read-only semantics this is a minor gap.

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 tool takes zero parameters, so there is nothing for the description to clarify beyond the schema; the 4 baseline applies. No parameter-related confusion is introduced.

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?

Names a specific verb+resource ('Listed meme coin market rows from GET /api/tokens') and explicitly distinguishes itself from the sibling memeswap_token, which serves single-address lookups. An agent can route correctly without opening either schema.

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?

States the trigger condition ('when the user asks for hot / new / trending memes to research before a buy') and the alternative ('Prefer memeswap_token for one address'). Both when-to-use and the disambiguating sibling rule are explicit.

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