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

Annotations already declare readOnlyHint=true and openWorldHint=true, covering the safety profile. The description adds two behavioral notes — output is 'normalized' and empty valid searches return empty arrays — which is genuine value, but it omits any detail on section types or result shape beyond what the output schema provides.

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-loads the purpose in the first sentence, then adds edge-case behavior and the sibling pointer in short, ordered sentences. Slight waste in restating both parameter schemas, but overall tight and well-sequenced.

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 an output schema present, the description need not explain return values, and annotations carry the safety profile. It covers purpose, the empty-result case, and a follow-up route, leaving only the meaning of 'sections' and search scope unspecified, which is a minor gap for a 2-param read tool.

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%, so the schema already documents both q and limit. The description merely restates them verbatim ('q: Search query. limit: Rows per section, default 10, max 50'), adding no new meaning such as expected query format or how limit interacts across the multiple sections.

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 verb and resource: 'Returns normalized CoinGecko search sections from the public website search JSON.' An agent can tell it is a general search over CoinGecko, and the source ('public website search JSON') is named. It stops short of differentiating itself from siblings like coingecko_categories or coingecko_exchanges.

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?

Names one alternative — 'Use coingecko_coin to retrieve coinGecko coin profile' — which gives a routing hint for follow-up detail lookups. It does not explain when to reach for this tool versus the many other coingecko_* search/list siblings, so guidance is implied rather than explicit.

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