list_test_customers

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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety and scope are covered. The description adds real behavioral value by disclosing that the result includes this server's live sessions and test customers busy elsewhere due to concurrent logins. It doesn't say how results are ordered, whether busy entries are flagged, or how a busy account should be interpreted.

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?

A single run-on sentence with an ungrammatical mid-sentence comma splice ('in an environment, the live sessions of this server and test_customers busy elsewhere') that forces re-reading. Nothing is front-loaded as a clear statement of action; the useful parenthetical is buried 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?

An output schema exists so return values needn't be spelled out, but for a two-parameter discovery tool with 0% parameter documentation and a crowded 16-tool sibling set, the description leaves the agent without a clear statement of purpose, parameter formats, or selection criteria. It communicates one useful fact (concurrent-session occupancy) inside otherwise confusing prose.

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 carries the parameter burden, and it only obliquely names both concepts ('a profile service', 'in an environment') without stating formats, valid values, or whether environment is optional or defaults to something. The 'service' format in particular is left completely undefined.

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 is a noun phrase fragment ('Test customers of a profile service in an environment...') that never states an action verb, so the agent must infer from the tool name that this lists something. It hints at the resource (test customers plus live sessions on this server) but doesn't cleanly say what the tool does or how it differs from siblings like list_services or session_variables.

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 parenthetical explains why a test customer may be unavailable (another VS Code window, agent, or CI holds the login), which gives interpretive context, but there is no explicit when-to-use instruction and no sibling is named as an alternative. An agent gets no routing guidance for choosing this over session_variables or check_service.

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