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

Annotations already cover the safety profile (readOnlyHint=true, destructiveHint=false, openWorldHint=false), yet the description still adds real value: it discloses that no source is auto-selected and no missing history is fetched, so the agent understands this is pure metadata discovery, not a fetch/backfill. That is exactly the kind of context annotations do not provide.

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 tight sentences, front-loaded with the core action and immediately followed by the scoping caveats. No filler or redundancy.

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 read-only enumeration tool with no output schema, the description conveys the return categories (identities and candle intervals) and the key constraint that sources/coverage stay separate with no backfill. It could say more about pagination, but the cursor/limit parameters already carry that.

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 description coverage is 43%, so the schema only partially documents the 7 parameters (limit, cursor, time_axis have text; asset_id, date_from, date_to, request_id do not). The description reinforces 'exact asset and UTC period,' nudging toward the required triplet, but adds no syntax or format detail and is silent on cursor, limit, time_axis, and request_id.

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?

Specific verb (List) plus resource (stored price-series identities and available candle intervals) scoped to an exact asset and UTC period. An agent knows exactly what is enumerated, though no sibling is named to sharpen the contrast (none is a close analogue anyway).

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?

No explicit when-to-use or when-not-to-use guidance, and no alternatives are named among siblings like read_price_context or discover_evidence. The sentence 'Sources and coverage remain separate; no source is selected automatically' describes behavior rather than when to pick this tool over another.

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