Find the nearest pharmacy locations to a US ZIP code, per chain.
``zip`` is a 5-digit US ZIP. Optional ``chains`` is a comma-separated list of
chain codes (e.g. "walgreens,publix"); default is all chains. ``limit`` caps
locations per chain. Coordinates are OpenStreetMap-sourced (ODbL).
| Name | Required | Description | Default |
|---|---|---|---|
| zip | Yes | ||
| limit | No | ||
| chains | No |
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
Changes observed during successful MCP inspections.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint, openWorldHint, and idempotentHint, so the safety profile is covered. The description adds useful context: coordinates are OpenStreetMap-sourced (ODbL) and limit is per chain. It does not contradict annotations, and the added data provenance is valuable beyond the structured fields.
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 three sentences with zero waste. The primary purpose is front-loaded, and parameter explanations are compact and clear. Every sentence contributes value.
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?
All required and optional parameters are explained, the output schema exists, and the description includes data source and default behavior. An agent has everything needed to call the tool correctly without additional inference.
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 0%, so the description must fully explain parameters. It does: zip is a 5-digit US ZIP, chains is a comma-separated list with default all, and limit caps locations per chain. This completely compensates for the schema gap and adds meaningful semantic detail.
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 specific verb and resource: 'Find the nearest pharmacy locations to a US ZIP code, per chain.' This clearly distinguishes it from sibling tools like search_drugs or compare_prices, which focus on drugs or pricing rather than geolocation. The purpose is unambiguous.
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 when to use the tool (when a user needs pharmacy locations near a ZIP) but does not explicitly mention alternatives or exclusions. It provides clear context but no guidance on when not to use it, which is a minor gap given the sibling list includes many drug-related tools.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
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