list_vdi_machines

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

Annotations already declare readOnly/idempotent/destructive=false, so the safety profile is covered; the description adds pagination behavior and enumerates returned item fields plus the full state value set, which is real value beyond the annotations. It stops short of detailing default page ordering or pagination termination, so not a 5.

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?

Two tight sentences; the READ marker and the core verb/resource are front-loaded, and the return-shape line earns its place by compensating for the absent output schema. No filler.

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 usefully enumerates the return fields and state enum values, so an agent knows what it gets back. Minor gaps remain (ordering, when pagination ends), but nothing essential to calling it 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 description coverage is 100% and all five parameters are documented in-schema (pool, state, limit, offset, target). The description only restates the pool/state filtering, adding no format or syntax detail, 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+resource (list Horizon desktop machines) with scope (filtered by pool id / state), and the '[READ]' prefix plus the field enumeration distinguish it from siblings like get_vdi_machine (single) and list_vdi_sessions. An agent can route to it without opening the schema.

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 clear usage context ('Verify pair for the machine write tools'), telling the agent it is the read-side companion to reset/set_maintenance/remove_vdi_machine. It does not, however, explicitly contrast against get_vdi_machine or list_vdi_sessions, nor state exclusions.

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