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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), so the description's job is added context. It does that by disclosing matching tolerance for case and partial input and by describing the result shape (ticker, name, slug, platforms with a price in the latest year, coin page URL), which is real information the annotations do not carry. It stops short of stating result caps or no-match behavior.

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 tight sentence pair: matching rules first, return fields second. The inline examples earn their space by demonstrating partial-match behavior rather than restating the schema.

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?

For a one-parameter read tool with no output schema, the description covers matching behavior and return fields adequately. Minor gaps remain around result limits and empty-result handling, but nothing blocks a correct call.

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% and there is only one parameter, so the baseline is already 3. The description earns above baseline by clarifying that the query is fuzzy and case-insensitive, with concrete examples ('eth', 'bitc', 'ripple') that tell the agent partial strings are acceptable.

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 (Find) and resource (coins) plus the three accepted identifier types (ticker, name, slug). None of the siblings (compare_platforms, price_history, value_portfolio) do identity lookup, so the agent can distinguish it without opening schemas.

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?

Usage is only implied: an agent can infer this is the resolution step before price/portfolio tools, but the description never says when to prefer it or what to do when nothing matches. No alternatives or exclusions are named.

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