altos_list_filesBrowse downloadable regional real estate data files. Returns catalog with file names, formats, and descriptions.
| Name | Required | Description | Default |
|---|---|---|---|
| type | No | Data type: "stats", "listings", "listings-new", "pendings" (default: "stats") | |
| region | No | Region code (default: "us_national") | |
| _altosKey | Yes | Altos Research API key |
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
Changes observed during successful MCP inspections.
Output schema / (root)Previous value: -nullNew value: +{
+ "description": "Raw JSON response from Altos API listing available data files",
+ "type": "object"
+}Input schema / examplesAdded value: +[
+ {
+ "_altosKey": "your-altos-api-key"
+ },
+ {
+ "_altosKey": "your-altos-api-key",
+ "region": "ca_los-angeles",
+ "type": "listings-new"
+ }
+]Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true, openWorldHint=true, idempotentHint=true, and destructiveHint=false, indicating safe, non-destructive behavior. The description adds the return content ('catalog with file names, formats, and descriptions'), which is consistent and provides some context, but no further behavioral traits.
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 sentence with no wasted words. It is front-loaded and efficiently communicates the tool's core purpose and output.
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?
Given the presence of an output schema (not shown) and rich annotations, the description covers the essential purpose. It likely does not need to explain return values in depth due to the output schema. However, a slightly more detailed description of what 'files' are available or how filtering works could improve completeness.
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%, so the input schema fully documents all three parameters (type, region, _altosKey). The description does not add any additional meaning or usage hints beyond what the schema provides. Baseline is 3, and no extra value is given.
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 clearly states the action ('browse') and resource ('downloadable regional real estate data files'), and mentions the return type ('catalog with file names, formats, and descriptions'). However, it does not explicitly differentiate itself from sibling tools like altos_active_listings or altos_inventory_trend, which likely have more specific focus.
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 provides no guidance on when to use this tool versus its siblings (e.g., altos_active_listings). There is no mention of context, prerequisites, or alternatives, leaving the agent to infer usage from the name alone.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Add one secure layer between your agents and this server.