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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), so the description's job is to add behavioural detail — and it does: it discloses that responses contain a verdict plus scholarly views plus halal alternatives, and that single ingredients and E-numbers are recognised inputs. That return-shape and input-tolerance information is genuinely useful and not derivable from the annotations.

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?

Front-loaded with the purpose, then dense parenthetical domain lists that carry real information rather than filler. The single long third sentence is slightly run-on, but nothing is wasted and the coverage list doubles as a scoping statement.

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 must explain returns — and it does (verdict, scholarly views, alternatives). Input is fully documented by the schema. The only real gap is the unresolved overlap with the specialised sibling tools, which the description never addresses.

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?

Only one parameter with 100% schema description coverage that already includes a worked example ('Is a credit card halal?'), so the baseline is 3. The description adds only a mild hint about acceptable input forms ('recognises single ingredients and E-numbers'), which is useful but marginal.

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 ('Ask') and resource ('is it halal' question) and enumerates the covered domains concretely, so the agent knows this is a broad religious-verdict Q&A tool. It does not, however, distinguish itself from specialists like check_crypto, check_medicine or check_ingredients, which cover overlapping territory.

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 rather than stated: the breadth of the domain list signals 'open-ended questions go here', but there is no explicit when/when-not and no routing rule against the sibling check_* tools. An agent must infer whether 'Is Bitcoin halal?' belongs here or in check_crypto.

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