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

Annotations already declare readOnlyHint, openWorldHint=false, and idempotentHint=true, so the safety profile is covered. The description adds the 'every city' scope and the optional filter behavior, but does not disclose output size, ordering, or pagination. With annotations present, this is adequate but not rich.

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 entire description is one dense sentence that front-loads the core action and resource, then enumerates return fields and the filter. There is no filler, repetition, or tangential detail.

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?

Despite having no output schema, the description lists every return field (Arabic/English name, country, coordinates, timezone, calculation method, canonical URLs) and documents the optional filter. Annotations cover safety and idempotency. Nothing essential is missing for an agent to invoke this tool correctly.

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%: the search parameter is already documented as filtering by city/country name in Arabic/English or by slug. The description adds the word 'optionally' and restates the name/country filter, which is marginal value beyond the schema. This matches the baseline for full schema coverage.

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 ('List') plus a specific resource ('every city that has a dedicated Wesalna prayer timetable page') and enumerates the exact return fields. This clearly distinguishes it from sibling tools like get_prayer_times or list_content.

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 makes clear that this is a discovery/list operation over prayer cities and that an optional filter by name or country exists. It does not explicitly name alternatives or give when-to-use versus get_prayer_times, but the purpose is specific enough that the intended context is evident.

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