Historical coin price chart

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

Annotations already declare read-only, idempotent, non-destructive. Description adds the plan limit of 7 days, which is useful context, but creates inconsistency with schema's 1825-day maximum. Does not disclose output format, but output schema exists to cover that.

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 sentences, no wasted words. Front-loaded with purpose, then constraint. Efficient for a simple tool.

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?

Given the rich annotations and output schema, the description is adequate for basic understanding but incomplete: lacks usage guidelines and fails to reconcile the plan limit with schema max. A more complete description would clarify the data granularity and conditions.

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 coverage is 100%, so baseline is 3. Description does not add any meaning beyond the schema's parameter descriptions; the 'up to 7 days' note is about output, not parameter semantics.

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?

Clearly states 'Historical price timeseries for a coin symbol,' which is a specific verb+resource. Differentiates from sibling tools like get_price (single point) and coin_markets (market overview), but lacks explicit differentiation from get_rate_history. The parenthetical plan limit adds context but is potentially confusing given the schema allows up to 1825 days.

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?

No guidance on when to use this tool versus alternatives like get_rate_history or coin_markets. No exclusions or prerequisites provided.

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