session_field_summary

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

No annotations exist, so the description bears full disclosure burden. It does add genuine behavioral detail — what each location evaluates and that elements report the 'worst Gauss point per element' — but never states that this is a read-only operation, nor anything about session state requirements or failure modes.

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?

Front-loaded with the core behavior, then a well-scoped sentence per location value. Dense with useful detail and essentially no filler, though the parenthetical variable lists are somewhat verbose.

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-value explanation is not owed, and the location semantics are covered. Still, with 0% schema coverage, model_part being undocumented in both schema and description leaves a real gap for a tool that can evidently be scoped to a sub-model-part.

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. It compensates well for location (explaining the nodes-vs-elements semantics and which variable families each accepts) and partially for variable (examples like DISPLACEMENT, VON_MISES_STRESS). But model_part and session_id are left completely unexplained anywhere.

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 (summarise) and resource (a field at the CURRENT time), plus the exact statistics produced (min/max/mean, component-wise for vectors) and where they occur. However, it never distinguishes itself from the sibling results_summary, so an agent must guess which summary tool is correct without opening schemas.

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 context is implied rather than stated: 'at the CURRENT time' hints this operates on a live session rather than stored result files, which implicitly separates it from results_summary/results_probe, but no explicit when-to-use or alternative is named. No prerequisites or exclusions are given.

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