Stock snapshots

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

Annotations already declare readOnly/idempotent/openWorld/non-destructive, so safety is covered. The description adds real behavioral context beyond them: change_pct is expressed as a fraction, change is derived specifically from last trade vs. previous close, and tickers with no data are surfaced in notes rather than silently dropped. No auth or rate-limit detail, but the value-add is genuine.

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 sentences, zero filler, and the resource scope is front-loaded before the field inventory. Every clause carries information an agent needs to interpret the response.

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 carries the return-value burden and does so well by listing the fields and the notes behavior for unmatched tickers. It could say a bit more about units/price semantics, but nothing needed to call 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?

There is a single parameter with 100% schema description coverage that already documents the format (['AAPL','BRK-B']) and the 1-200 bound. The description adds nothing about the tickers argument, so the baseline 3 applies.

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 ('Latest state per stock ticker') and enumerates exactly which fields the snapshot contains, which implicitly separates it from the single-datatype siblings (market_latest_trades, market_latest_quotes, market_latest_bars). It stops short of naming those siblings, so the differentiation requires the agent to infer it.

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: the field list suggests this is the one-shot aggregate call to prefer over several single-type calls, but there is no explicit when-to-use statement, no exclusion, and no named alternative. Adequate but with a clear gap.

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