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

Annotations already cover readOnlyHint and idempotentHint, so safety profile is clear. The description adds what state is returned (login, seq numbers, connection details), which is useful behavioral context beyond the annotations. But it doesn't describe whether live state is real-time vs cached, or any rate limits/auth needs.

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?

Single sentence, front-loaded with the verb and resource, then parenthetical detail. No wasted words.

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?

Given no output schema, the description tells the agent the categories of returned data (settings, login state, sequence numbers, connection details), which is sufficient for a read-only getter. Missing is guidance on the apiKey param and edge cases when session not found, but overall complete enough.

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 33%; session param is documented (references fixsim_list_sessions), but instance and apiKey lack descriptions. The description adds no parameter semantics beyond what schema provides, and only partially compensates 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?

Specific verb (Get) + resource (one FIX session) with explicit scope ('one FIX session's'). Distinguishes from sibling fixsim_list_sessions (plural) by emphasizing the singular session and returns settings plus live 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?

The parenthetical hints at when it's useful (checking login status, sequence numbers, connection), implying usage for inspection. But there's no explicit when-to-use versus fixsim_list_sessions, and no stated prerequisites or exclusions.

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