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

Annotations already declare readOnlyHint, idempotentHint, and non-destructive behavior, and the description adds substantial context beyond that: forward-only record traversal, source label semantics, per-record SHA-256 hashes, and exact payment/auth conditions for free vs full scope. No contradiction with annotations.

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?

The description is long and dense, but every clause carries useful information and the 'Free slice, paid full record' opening is a strong front-loaded summary. It loses one point because the free/full rules are woven into a long run-on structure that could be clearer as a short list.

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 output schema, complete parameter schema, and strong annotations, the description covers all necessary call semantics: coin identification, free vs full behavior, payment methods, authentication for paid access, record contents, and data source. Nothing needed to invoke the tool correctly 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?

Schema coverage is 100%, so the baseline is 3. The description adds meaningful semantics beyond the schema by explaining the real-world consequences of scope: what 'free' returns, what 'full' returns, how and when payment triggers, and that no charge occurs before the free slice is exceeded.

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 states a specific resource ('Score history of one coin') and a precise resource shape: every recorded change to its 8 metric scores, with dated records, TVR Score, method version, source label, public reason, and SHA-256 hash. This clearly distinguishes it from sibling tools like get_tvr_score (current score) and get_full_breakdown.

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?

The description gives explicit decision guidance for scope: free returns the last 90 days or last 3 records with no payment, while full requires a Premium key or per-pull payment beyond the free slice. It does not explicitly name alternative sibling tools or state when not to use them, so it stops short of a 5.

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