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

Annotations already declare readOnlyHint and idempotentHint, so safety is covered, but the description adds genuine value by enumerating the returned states and clarifying that 'waiting' means nobody has logged on yet. This outcome-level detail goes beyond what the structured fields provide.

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 sentences, question first, with no filler. The state enumeration is compact and every clause contributes meaning.

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 read-only status check with annotations covering safety and no output schema, the description is largely sufficient because it names the possible return states. The one notable gap is that it never connects to the sessionId parameter the caller must supply.

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 the single required sessionId (a uuid) is never mentioned in the description. There is no explanation of which session to query or how the ID is obtained, so the description 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?

The description poses a specific diagnostic question ('Is the user's FIX engine connected to the sandbox session?') and enumerates the possible states, so the agent knows exactly what this checks. It is distinguishable from list-style siblings, though it does not explicitly contrast with sandbox_get_session, which may also surface session state.

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?

There is no explicit when-to-use guidance or statement of alternatives. The nearest sibling, sandbox_get_session, plausibly reports the same connection state, yet the description says nothing about which to pick or when a status check is warranted over fetching the session itself.

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