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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety is covered; the description adds substantive behavior beyond that: the exact screening thresholds applied, the exchange coverage (NASDAQ, NYSE, ASX, Bursa, SGX), and the fact that verdict-change dates are returned from a public ledger. It does not mention rate limits or auth, which is a minor gap.

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 screening criteria are front-loaded immediately after the verb, followed by return behavior, coverage, and input format in descending priority. No sentence is filler; even the coverage and ticker clauses prevent wrong invocations.

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 correctly compensates by stating what comes back (a verdict plus the dates it changed). For a single-parameter read tool with annotations covering safety, this is nearly complete; only the exact response shape and any rate limits are left unspecified.

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 meaningfully enriches the single parameter by showing exchange-suffixed ticker formats (NVDA, CSL.AX, 1155.KL, D05.SI) that clarify how non-US listings must be passed. This adds real syntax guidance beyond the schema's own example.

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 (screen) and resource (a listed company), plus the explicit criteria family (AAOIFI-style: business activity, debt/cash <30% of market cap, interest income <5% of revenue). It is clearly distinct from a generic stock lookup, though it never names the sibling recent_halal_verdict_changes to route between them.

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 implied by the phrasing 'Pass a ticker ... or a company name,' which tells the agent how to invoke it, but there is no explicit when-to-use or when-to-prefer-the-sibling guidance. An agent must infer that this is the per-company deep screen while the sibling is the changelog feed.

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