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

Despite annotations only flagging non-readonly, non-destructive, the description discloses the actual side effects: two pressure cases written, the analysis set-up removed, a backup of the model's own springs kept for undo, and a minutes-long runtime. That is exactly the mutation/undo context an agent needs beyond the hints.

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 action and packed with useful detail in two sentences, no filler. The second sentence is dense with several clauses (runtime, job polling, apply), which slightly hurts scannability but nothing is wasted.

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 complex 23-param mutating runner with no output schema, the description covers the process, job behavior, undo backup, and apply semantics well. It omits preconditions like the confirmPlanHash flow and the meaning of most geometric/thermal parameters, leaving some gaps.

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 only 43% across 23 parameters, so the description should compensate but mostly doesn't. It does add real meaning for 'apply' (preview vs write), but the many bare numeric parameters (psi, gammaQ, skewDeg, etc.) get no clarification here or in the schema.

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 and resource: 'Runs the PD 6694-1 Annex A iteration' with concrete mechanics (Winkler springs, settling loop, pressure cases written). It is clearly differentiated in substance from pd6694_ssi_plan and pd6694_route_a, though it never names a sibling to contrast against, which keeps it short of a 5.

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?

'Previews unless apply: true' gives explicit dry-run vs commit guidance, and 'runs as a job (poll job_status)' tells the agent how to follow up. It stops short of naming alternatives (e.g., when to prefer pd6694_ssi_plan) or stating when not to use it.

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