session_close

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

With no annotations, the description carries the full behavioral burden and does well: it discloses that Finalize() flushes output processes (VTK/GiD, restart files) before the worker process group is terminated, and that the call is idempotent on closed/dead sessions. It does not mention permissions, cost, or failure modes, leaving some gaps for a destructive lifecycle operation.

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?

Three tight sentences, front-loaded with the action, then the mechanism, then the safety note. No restated schema, no filler; every clause adds information an agent needs.

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?

An output schema exists, so return values need not be explained, and the annotations are absent, meaning the description must cover the safety profile — which it largely does through the termination and idempotency disclosures. The remaining gap is relational context (how a session relates to jobs/studies in this tool set).

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%, so the description must compensate, and it does for the only non-obvious parameter: finalize=True is explained in terms of the concrete flush behavior and its default. session_id is undocumented but its meaning is self-evident from the tool name and required-parameter status.

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 and resource ('Close a session') and immediately qualifies the operation by describing the finalize path and process termination. It never names or contrasts with close-adjacent siblings like job_cancel or study_cancel, so an agent must infer the scope, but the core purpose is unambiguous.

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?

Usage is implied rather than stated: nothing says when to prefer session_close over job_cancel/study_cancel or what state a session must be in. The one explicit usage cue is the idempotency guarantee ('Safe to call on an already closed or dead session'), which is genuinely useful but is the only routing guidance present.

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