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

Annotations already declare readOnly, idempotent, non-destructive, closed-world behavior, so safety needs no restating. The description adds real behavioral context beyond that: results are field ids plus a count of how many coins have each field, and the list is filterable by words in the name or id. It stays silent on the 40-item default cap and whether the list is ever truncated, which is the remaining gap.

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 short sentences with the purpose and the payload front-loaded, followed by the search affordance. The id examples are genuinely load-bearing but partially duplicate the examples already in the schema's `query` description, so it is efficient rather than maximally tight.

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 two-optional-parameter lookup with rich annotations and no output schema, the description covers what is returned (field ids with coin counts), why it matters (the vocabulary screen_assets accepts), and how to narrow it. Only pagination/default-limit behavior is left unstated.

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 both `limit` and `query` are already documented with examples in the schema itself. The description only reinforces the query concept with 'Search them by words' and supplies id-format examples, adding marginal meaning over the schema; 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?

States a specific verb and resource ('List the fields screen_assets can test') and ties the output to the sibling tool that consumes it, which separates it from generic metadata siblings like get_metrics_list or get_metric_metadata. Concrete id examples (market.Mvrv, derivatives.FuturesFundingRatePerpetual) make the resource unambiguous.

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?

By naming screen_assets as the consumer, it implicitly tells the agent to call this before/instead of guessing field names when screening assets, and 'Search them by words' points at the query path. It does not explicitly exclude or compare against get_metrics_list / get_metric_metadata, so usage context is clear but not fully routed.

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