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

With no annotations provided, the description carries the full burden. It discloses useful behavior: a maximum of 250 results, optional filtering by a CoinGecko category, and the data categories are enumerated. However, it omits read-only/mutation status, data freshness, rate limits, and the source API beyond the category examples.

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 dense sentences, with the primary purpose front-loaded and the optional category filter and intended uses following immediately. No filler or repetition.

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?

An output schema exists, so the description need not explain return values, though it usefully lists the key fields. For a two-parameter read tool with no annotations, the description covers purpose, scope, filter options, and usage context; only freshness and rate-limit behavior are 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?

Schema description coverage is 0%, so the description must compensate. It implies the 'limit' parameter is a top-N count capped at 250, and it explains 'category' as a CoinGecko category with four example slugs. It still does not specify the default limit (50), the category format, or that limits above 250 are truncated versus rejected.

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 specific resource (top cryptocurrencies by market cap), a clear cap (up to 250), and enumerates the returned fields. It does not explicitly distinguish itself from close siblings like crypto_market_overview, crypto_trending, or crypto_coin_info, so an agent has to infer the difference from the name.

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?

"Use for market overviews and screeners" gives a positive usage context, but it offers no alternatives, exclusions, or prerequisites. An agent cannot tell from the description alone when to prefer crypto_market_overview or crypto_trending instead.

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