fastly_list_versions

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

No annotations are present, so the description carries full responsibility for behavioral disclosure. It does state 'Read-only', which is a positive behavioral trait, and mentions the need for a token. However, it does not describe the response format, error handling, or any side effects beyond being non-mutating. For a simple read operation this is adequate but minimal.

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, concise sentence that front-loads the key read-only trait and lists the required inputs. There is no redundancy or unnecessary detail, and every word contributes to the tool's understanding.

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?

For a simple list operation with only two parameters and no output schema, the description covers the essential aspects (read-only, required identifiers). However, it does not specify the expected return format (e.g., an array of version objects), mention pagination, or note potential error conditions. It is acceptable for a basic tool but leaves some operational details unaddressed.

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 0%, so the description must compensate by explaining parameter meaning. It only says 'Requires serviceId and a user token' – this essentially repeats the schema field names without adding semantics such as 'the identifier of the Fastly service' or 'the API token used for authentication'. The description adds minimal value beyond the schema itself.

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 states a specific verb ('list') and a specific resource ('versions for a Fastly service'), clearly distinguishing it from sibling tools like fastly_list_services (which lists services) and fastly_get_config (which fetches configuration). The purpose is unambiguous.

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 notes the tool is read-only and requires serviceId and a user token, but does not provide explicit guidance on when to use this versus alternatives like fastly_list_services or fastly_get_config. The usage context is implied by the tool name and resource, but no direct differentiation or when-not-to-use conditions are stated.

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