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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, so the description need not repeat those. It adds minimal context by clarifying that the returned settings are the 'currently active' ones, but it does not describe behavior for invalid userIds or whether there are any side effects. No contradiction with annotations exists.

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 description is concise and front-loaded with the main action and object. The second sentence, 'Read-only operation', is redundant with annotations but is short and does not significantly detract from clarity.

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?

For a simple read-only tool with one documented parameter and an output schema, the description covers the essential semantics. It lacks sibling differentiation and usage conditions, but the context signals and schema fill most gaps.

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%, and the single parameter 'userId' is already described as 'Unique user identifier' in the schema. The description's mention of 'for a user' aligns with the parameter but does not add new semantic detail beyond the schema.

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 uses a specific verb ('Returns') and names the resource ('currently active calculation settings and preferences for a user'), making the tool's purpose clear. It is distinguishable from siblings like get_next_prayer or get_today_prayer_times by focusing on settings and preferences, though it does not explicitly name a sibling to differentiate from.

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 description implies the tool is for retrieving a user's active preferences but does not state when to use it over alternatives such as configure_prayer_preferences or get_prayer_status. The 'Read-only operation' note signals safety but offers no explicit when-to-use or when-not-to-use guidance.

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