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

Annotations already declare readOnlyHint=true and idempotentHint=true, covering safety and repeatability. The description adds specific output behavior—bearing from true north and great-circle distance to the Kaaba—which goes beyond the annotations and helps the agent understand what the call returns.

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 a single, focused sentence with zero filler. It front-loads the primary output (bearing) and then the secondary (distance), making it immediately clear and efficient.

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 two numeric parameters and no output schema, the description covers the core purpose and outputs. It does not specify units for the distance (e.g., kilometers or miles) or the bearing (degrees), which is a minor but useful detail that is absent.

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?

The schema provides 100% description coverage for both parameters (latitude and longitude), so the baseline is 3. The description adds only the implicit 'location' context and does not elaborate on parameter formatting or units beyond what the schema already documents.

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 states a clear verb (Return), a specific resource (Qibla bearing and great-circle distance to the Kaaba), and the scope (for a location). It distinctly differentiates from sibling tools like get_prayer_times or convert_hijri_date, leaving no ambiguity about what this tool does.

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 clearly implies this tool is for location-based Qibla direction, and given the sibling list, no other tool appears to serve this function. However, it does not explicitly mention when not to use it or name an alternative, so it lacks explicit exclusion guidance.

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