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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so safety is covered. The description adds that the tool returns both a functional classification and scholarly views, which is useful content context, but it says nothing about coverage limits, handling of unknown tickers, or response shape.

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 first two sentences ("Halal or Not. Is this cryptocurrency halal?.") duplicate the name and title verbatim and earn no place. The substantive sentence is dense and informative, but the definition is not front-loaded with it.

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 usefully sketches what comes back (a functional classification plus scholarly views), which is the key thing missing from structured fields. For a one-parameter read-only lookup it is nearly complete, lacking only edge-case behavior.

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 100% for the single 'coin' parameter (name or symbol, with examples), so the schema does the heavy lifting. The description adds no syntax, formatting, or ambiguity guidance beyond what is already structured.

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 second sentence names a specific verb (classifies) and resource (a coin) and enumerates the classification buckets (lending, gambling, meme, stablecoin, staking, general-purpose), which separates it from halalornot_check_fund and halalornot_screen_stock. The opening two sentences merely restate the tool name and title, adding no new information.

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: an agent can infer this is for individual coins versus the fund/stock siblings, but the description never states when to use it, when not to, or names an alternative. No prerequisites or input constraints are given.

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