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

Annotations already declare readOnly, idempotent, non-destructive and open-world, so safety is covered. The description adds genuine behavioral context: each row carries venues, chains, outcomes and 24h stats, and prediction rows expand to every outcome, which explains output shape and result-size blowup. It does not discuss rate limits or result caps beyond limit, so not a 5.

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-loaded with purpose, then filters, sort, paging, then caveats — a sensible order with no filler sentences. It is somewhat run-on and spends words re-listing kind/venue/chain/class/tag/feed and sort values that the schema already enumerates, which is the only real waste.

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 14-parameter, zero-required browse tool with no output schema, the description covers what a row contains, how paging works, and the two biggest footguns (silent outcome fan-out and noisy spot change metric). Missing only explicit sibling routing and any note on default ordering behavior when sort is omitted.

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 earns a bump by explaining operator intent behind key parameters — kind=perp for movers, min_liquidity semantics ('unless filtered by liquidity'), and the practical limit ceiling of 5 for prediction rows. It still largely restates the filter/sort enumerations already in the schema.

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 ('Browse or filter the Discover index') and enumerates the exact asset surface: spot tokens, tokenised stocks, perps, prediction markets. That scope makes it distinguishable from siblings such as search_assets, list_perp_markets and discover_categories without opening any schema.

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 real conditional guidance: use kind=perp for movers, avoid spot change_24h because it is noise from illiquid pools, and keep limit small (<=5) for prediction rows. What it lacks is explicit routing to named alternatives (e.g. when to prefer search_assets or list_perp_markets instead), so 4 rather than 5.

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