fly_list_machines

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

Annotations already declare readOnly, idempotent, non-destructive, and openWorld, so safety is covered. The description adds only the word 'all', implying no filtering/pagination, and says nothing about whether deleted machines appear by default or how many results are returned.

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 front-loaded sentence with no waste. It is efficient but arguably under-specified rather than merely concise.

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?

A list tool with 3 undocumented parameters, no output schema, and no explanation of default inclusion of deleted machines or result format. An agent could call it, but not confidently predict what it gets back.

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% and all 3 parameters are undocumented in the schema. The description explains only app_name implicitly; api_key and especially include_deleted (which changes the result set meaningfully) are never addressed, so it fails to compensate for the coverage gap.

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?

Names a specific verb (List) and resource (machines) scoped to a Fly.io app, so an agent can tell it apart from fly_create_machine. It does not distinguish itself from other Fly list-style siblings (fly_list_apps, fly_list_volumes), but the resource nouns are different enough.

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 gives no when-to-use/when-not guidance and never mentions the sibling tools. The read-only nature is implied by 'List', but nothing states e.g. that this is for inspection before machine operations.

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