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

Annotations already declare readOnlyHint=true, so safety is covered. The description adds no behavioral context beyond that — no pagination behavior for a 'list all' call, no rate limits, no ordering guarantees, and no auth note. The API path is a mapping, not a behavioral trait.

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?

One compact sentence plus an endpoint reference, with the scope and output fields front-loaded. Every element is short, though the endpoint string is arguably redundant for an agent.

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?

With no parameters and no output schema, the description usefully enumerates the returned fields (id, name, npi, address), which substitutes for a missing output schema. It stops short of covering pagination or volume expectations for an unfiltered organization-wide list.

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 tool takes zero parameters, so the baseline is 4. The parenthetical field list describes return values rather than inputs and therefore adds nothing to parameter understanding.

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?

Specific verb (List) plus resource (Facilities) with explicit scope (under your Metriport Organization) and the fields returned. It is distinguishable from metriport_get_facility only by the plural 'List all', so sibling differentiation is implied rather than stated.

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?

No when-to-use guidance, no preconditions, and no mention of the sibling metriport_get_facility that would be the alternative for fetching a single facility. The agent must 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.