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

Annotations already declare read-only/idempotent/non-destructive, and the description adds what annotations cannot: the 404 behavior for a non-owned watchlist id, that data is scoped to the API-key owner, and the safety_tier semantics (green/grey/red, with an explicit warning that grey is NOT a red flag and that agent buys are refused on red).

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 purpose, batching benefit, and the alternative, with the safety_tier guidance placed where it matters. It is somewhat dense: enumerating every returned field is partly redundant given an output schema exists, though the semantic notes (gray = not scored, red = Moby blocks buys) earn their space.

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 tool with an output schema and rich annotations, the description closes every practical gap: default-list behavior, auth scoping, error behavior, and how to interpret returned tiers. Nothing an agent needs to call it correctly or to triage results is missing.

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?

watchlist_id is covered in both schema and description, with the description adding the default-list rule and the 404 failure mode. The network parameter is undocumented in prose, but it is a const ('solana'), so it needs little explanation; this small gap keeps it below 5.

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 the specific resource (tokens on one of the user's watchlists) and the batching behavior (market data in ONE call, replacing a per-token get_token_overview). It explicitly distinguishes itself from both get_token_overview and get_my_watchlists, so an agent can pick it without opening the 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?

Gives explicit conditional usage: omit watchlist_id for the default list on this network, otherwise pass an id from get_my_watchlists. It also points to get_token_overview for the full picture of one token, and rules out asking about another wallet entirely.

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