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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is covered. The description adds genuinely new behavioral context: the return type (list[dict]) and the structured error envelope with code/retryable fields, which tells the agent how to react to failure. It does not cover rate limits or exchange availability.

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?

The purpose is front-loaded in one line, followed by a compact Args block and return note. Every section carries information, though the Args list is somewhat schema-like in form. No filler or repetition.

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 5-parameter read-only scanner with an output schema, the description covers purpose, every parameter's meaning, and failure behavior. It does slightly restate return values that the output schema already defines, and it omits which exchanges are valid, but nothing essential for invocation is missing.

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 largely succeeds: it defines min_volume_ratio as a multiplier, min_price_change as a percentage, rsi_range with concrete bucket values (<30/30-70/>70/any), and limit as max 30. Only 'exchange: Exchange name' is left thin, with no list of valid exchanges.

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?

The description states a specific verb+resource: a scanner combining volume and technical (RSI) analysis. Combined with the parameter list, an agent can tell it finds volume-spike candidates filtered by RSI state. It never distinguishes itself from the similarly-named sibling volume_breakout_scanner or bollinger_scan, so differentiation is left to inference.

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?

Usage is only implied through the parameter documentation (volume multiplier, price change %, RSI buckets), which conveys how to tune the scan but not when to choose it over volume_breakout_scanner or combined_analysis. No exclusions, prerequisites, or alternative routing are given.

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