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 useful context that data comes from public website chart JSON endpoints and is normalized, hinting at a scraped/derived source, but discloses nothing about pagination, ordering, or how missing data is handled.

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?

A single front-loaded sentence with no filler; it states the operation and source immediately. It is efficient, though it omits any contextual routing information that would have earned a 5.

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 needn't explain return values, and the annotations cover safety. However, given the many coingecko_* siblings, omitting any guidance on when to prefer this endpoint over coingecko_global leaves a real gap for correct tool selection.

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 kind, limit, and range are already fully documented in the schema. The description adds no syntax, default, or format detail beyond the schema, so the baseline 3 applies.

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?

The description names a specific verb (Returns) and resource (normalized chart series) and even identifies the upstream source (CoinGecko public website chart JSON endpoints). It is clear what the tool does, but it does not distinguish itself from the sibling coingecko_global or state which chart kinds it serves, leaving the agent to infer the distinction.

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?

There is no guidance on when to use this tool versus coingecko_global or the other coingecko_* endpoints, and no mention of prerequisites or selection conditions. The agent gets no when/when-not framing.

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