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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive), and the description layers on non-obvious behavior: CSV output shape ('one row per trading day, most recent last'), the 50-day default, self-disclosure when more history exists, and JSON candidate fallback on ambiguity. That is exactly the extra context annotations cannot convey.

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 single dense paragraph is front-loaded with the core purpose and output format, then tacks on defaults and ambiguity handling. Nearly every clause carries information, though the symbol-vs-index and ambiguity points could be separated for faster scanning.

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 steps in to describe the return format, row ordering, default window, and the JSON-candidates alternative response, plus how to page. Nothing an agent needs to invoke it correctly 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 coverage is 100%, so the baseline is 3, but the description adds end-to-end meaning: it ties limit/offset to chronological vs most-recent-first ordering and explains what happens when symbol resolution is ambiguous (candidates returned, re-call with exact symbol). This goes beyond the per-parameter text.

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 gives a specific verb and resource ('Get pre-computed daily technicals') and enumerates the payload (moving averages, relative-strength rating, 52-week range, volume anomalies). It also states the dual coverage (CSE stock OR sector/headline index), which separates it from raw-data siblings like get_ohlc_data and index-only siblings like get_index_data.

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?

It clearly frames when the tool applies ('for a CSE stock OR a sector/headline index ... one tool for both') and explains paging ('how to page further back with offset') and the ambiguous-input fallback. It stops short of naming an explicit alternative for raw price history, so the routing guidance is strong but not exhaustive.

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