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

Annotations already cover safety (readOnly, idempotent, non-destructive, closed-world), and the description adds real substance: the three verdict buckets, the plain-language reason, the business test and the interest-bearing debt ratio. The 'a screen, not a fatwa' line usefully scopes the authority of the result, though rate limits or how ambiguous tickers are resolved are unstated.

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 front-loaded sentences carry the trigger, the input shape, and the return contents, with the caveat placed last. No filler or repeated schema constraints beyond the necessary range.

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 a single well-documented parameter and no output schema, the description does the extra work of enumerating what each verdict includes, so an agent knows what comes back. 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?

Schema description coverage is 100% and the schema already states '1 to 10 tickers or company names' with min/max item bounds. The description restates the same 1-to-10 range without adding format hints, so it neither compensates for nor exceeds the schema. 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?

States a specific verb and resource ('check whether stocks are halal') plus the screening framework (AAOIFI-based) and the exact verdict set. An agent can distinguish it from explain_stock or compare_stocks without opening the 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?

The opening clause gives a concrete trigger ('when the user asks whether one or more stocks are halal, Shariah-compliant or permissible'). It does not explicitly route away from siblings like explain_stock or compare_stocks, which an agent may also want when the question combines compliance with analysis.

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