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

Annotations already declare readOnlyHint=true, openWorldHint=true and destructiveHint=false, so the safety profile is covered. The description goes beyond them by disclosing the failure contract: a structured error envelope `{error: {code, retryable}}` on ANY failure. It does not cover pagination or ordering, but that is minor given the output schema.

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 the core purpose in one sentence, then routing guidance, then the example, then a compact Args block. The long exchange list is dense but earns its place given zero schema coverage. The aside about the canonical tool name is mildly defensive but prevents a realistic hallucination.

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 4-parameter, zero-schema-coverage scan tool this is complete: purpose, routing, valid enum values, sensible defaults, error behavior, and return type are all present. An output schema exists, so return-value detail beyond `list[dict]` is not required.

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 0%, so the description carries the full parameter burden and does it well: it enumerates valid crypto and stock exchanges, lists the exact timeframe enum, supplies per-timeframe squeeze thresholds, states the bbw_threshold default and the limit cap (max 100). This is meaningfully richer than the bare schema defaults.

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 — scan a whole exchange for assets with low Bollinger Band Width — and explicitly scopes it as exchange-wide rather than per-symbol by naming `coin_analysis` as the single-symbol alternative. An agent can distinguish it from siblings like `coin_analysis` or `volume_breakout_scanner` 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?

Gives an explicit when-to-use (`scan a whole EXCHANGE`), an explicit when-not-to (`for the Bollinger read of ONE symbol, call coin_analysis instead`), and a concrete invocation example with filled arguments. It even pre-empts a likely hallucinated alternative tool name.

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