get_vdi_session_stats

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

Annotations already declare readOnly, idempotent, non-destructive, and openWorld, so the safety profile is fully covered by structured data. The description adds the '[READ]' marker and clarifies that results are aggregates rather than rows, but provides no behavioral details such as scope of aggregation, freshness, or failure modes. With annotations carrying the safety burden, a 3 is appropriate.

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 compact sentences, front-loaded with what it returns and followed by the disambiguation from its sibling. Every sentence earns its place with 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?

There is no output schema, so the description usefully enumerates the aggregate categories returned (by state/protocol, current concurrent, busiest pools), which is enough for an agent to know what to expect. It stops short of any detail on granularity, time window, or shaping of the response, so it is not fully complete.

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 100% and the single 'target' parameter is documented in the schema as the Horizon target from config.yaml. The description adds no syntax, default, or selection detail beyond that, 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?

The description gives a specific verb and resource ('Session statistics') and enumerates exactly what it reports: concurrency by state/protocol, current concurrent count, and busiest pools. It explicitly differentiates itself from list_vdi_sessions as the aggregate reporting counterpart, so an agent can pick 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?

It names the alternative (list_vdi_sessions) and the condition that selects this tool — wanting aggregate numbers rather than per-session rows. That is clear routing guidance, though there is no explicit when-not or prerequisite/permission guidance.

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