list_environments

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

Annotations already declare readOnlyHint=true, so safety is covered; the description goes further by disclosing the return shape (raw array of {id, name, description}), the meaning of an empty array, and the per-project scoping. Useful behavioral context beyond the annotation, though auth/permission needs are unstated.

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?

Three tight sentences, front-loaded with the action and scope, then the reason to call it, then the return format. Every clause carries information an agent needs; nothing is redundant.

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 output schema, the description correctly takes on the burden of describing the return value (raw array, empty-array semantics). Combined with the annotation covering safety and the schema covering the sole parameter, an agent has everything needed to call it correctly.

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% and the single parameter's fallback behavior (ZEPHYR_DEFAULT_PROJECT_KEY) is fully documented in the schema. The description only hints at it via the 'projectKey=…' endpoint snippet, adding no syntax or format detail beyond the schema, 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?

States a specific verb and resource ('List the Zephyr Scale environments of a project') and even names the underlying endpoint. It implicitly contrasts with the sibling create_environment, but never names or differentiates siblings explicitly, so it stops short of a 5.

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 a clear reason to call it: environments are referenced BY NAME and case-sensitively in test run items and results, so this tool is how you obtain the exact spelling. It supplies context but does not state exclusions or point to create_environment as the alternative for adding one.

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