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

Goes well past the read-only/idempotent annotations: it discloses that cadence is non-uniform (roughly 15 minutes since March 2026, sparser before), that the response reports observedIntervalMinutes which must be read before treating data as fixed bars, and that intraday history is tier-gated. This is exactly the kind of caveat that prevents misanalysis.

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 purpose, then alternatives, then caveats, then limits – a logical order with no filler. It is fairly dense at five sentences, but each sentence carries distinct information (cadence warning, bucketing, window cap, tier note).

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?

With no output schema, the description compensates by naming the key response field (observedIntervalMinutes) and describing bucket behavior. Minor gaps remain: no mention of the response envelope (e.g., observation array shape or pagination/truncation behavior on long windows).

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, but the description adds real value beyond it: the 92-day maximum window, tier-dependent reach-back, and the semantics of interval bucketing ('keeping the last observation in each bucket'). It does not cover type or the from/to defaults, which remain schema-only.

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 the specific verb and resource ('Get every price observation mkts made of one symbol inside a time window') and immediately contrasts it with the daily-close alternative, so an agent can distinguish it from get_asset_series and get_price_history without opening a 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?

Explicitly names the three usage cases (intraday movement, timing questions, session behavior) and routes the daily-close-over-months case to get_asset_series by name. That is a clear when-to-use plus a named alternative.

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