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

With no annotations, the description carries the full burden and does so thoroughly: daily refresh with an as_of timestamp, coins appearing in multiple categories, partial coverage (only larger coins listed), omitted empty categories, result-size growth characteristics, and both error states (503 not_ready before first refresh, not_found when categories are disabled). This is unusually complete disclosure of mutation-free but non-obvious 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?

Front-loads what the tool returns before adding cadence, join guidance, and error semantics. Every sentence carries information, though the parenthetical about 'both copies of the result' is slightly convoluted and could be tightened.

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?

An output schema exists, so return-value structure need not be restated, and the description fills the remaining gaps: freshness, coverage limits, join semantics, and failure modes. Nothing an agent needs to call and interpret this 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?

The tool takes zero parameters, so there is nothing for the description to disambiguate; baseline for a parameterless tool is 4. The description correctly implies a no-argument call.

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?

Names a specific resource (coin categories) plus the underlying endpoint, and states exactly what each entry contains (category id/name plus catalog uids). It also distinguishes itself from siblings by naming get_rates and search_assets as join partners rather than alternatives, so an agent can place it precisely in the toolset.

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?

Gives a concrete usage path — join category uids with uids from get_rates or search_assets to group holdings — and explains the daily refresh cadence. It stops short of stating when NOT to use it (e.g. vs get_meta or get_daily), so it is clear context without explicit exclusions.

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