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

Adds substantial context beyond the readOnly/idempotent annotations: what the payload contains (recent probes, newest first, timestamp, pass/fail, latency, error, hourly-probe coverage flag), the authorization model, and the specific 403 failure mode for unclaimed workspaces.

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?

Front-loaded with the core action, then return shape, then prerequisites — a sensible order with no filler. The first sentence is a long comma-chained list that could be split, but every clause carries information.

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?

There is no output schema, so the description's enumeration of returned probe fields is exactly the compensation needed. Auth, failure mode, and result ordering are all covered; nothing an agent needs to call and interpret this 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?

Schema coverage is 100% and the single parameter already documents format (uuid) and provenance ('id on a list_functions result'). The description's 'Pass function_id' adds no meaning beyond that, so the baseline 3 applies.

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?

Opens with a specific verb + resource and scope: 'Read the endpoint health of one of your external functions' — clearly a diagnostic read on a single function, distinguishable from get_function (config) and run_function_health_probe (which triggers a probe rather than reading results).

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?

Gives concrete preconditions for use: owner-only, Last Price credential required, and a claimed workspace (sandbox key refused with 403). It stops short of naming alternatives (e.g., 'use run_function_health_probe to generate a new probe' or 'use list_functions for the id'), so the routing is implied rather than explicit.

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