İstanbul nöbetçi eczaneler (bugün, ilçe bazında)

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

Annotations already mark this read-only/open-world; the description adds meaningful behavioral context beyond them: the data source (İBB Şehir Haritası's service), the fact the duty roster changes daily, and that the response carries a retrieval time. No contradiction with 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?

The description is compact and front-loaded with the main result and scope. The Turkish and English sentences are near-duplicates, which introduces slight redundancy, but the overall length is justified and the key usage notes appear at the end.

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 single optional parameter with an output schema and read-only annotations, the description is complete: it states the city, day scope, returned fields, optional district filter, data source, and freshness/dynamic behavior. Nothing necessary to call it correctly is missing.

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 already covers `ilce` with an example, and the description adds valuable filter semantics: if supplied, only that district is returned, implying omission returns all districts for Istanbul. This is useful beyond the raw parameter name and type.

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 names a concrete resource and scope: today's on-duty pharmacies in Istanbul, and enumerates the returned fields (name, district, address, phone, coordinates). It also identifies the source service, which distinguishes it clearly from the sibling izmir_nobetci_eczane for İzmir.

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?

It clearly states this is for Istanbul today and explains the optional `ilce` filter ('`ilce` verilirse yalnızca o ilçe'). It does not explicitly mention the sibling `izmir_nobetci_eczane` as the alternative for İzmir, but the city-specific wording makes the intended context unambiguous.

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