Pause charging

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

The lead 'CHANGES STATE' plus the state precondition adds real behavioral context beyond the annotations, which already cover idempotency and non-destructiveness. It also discloses the error behavior (returns an explanation), though it does not detail auth requirements or what the paused state persists.

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 tight clauses, front-loaded with the state-changing nature and the validity condition. Zero filler; every element earns its place.

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 one-optional-parameter state-change tool with an existing output schema, the description supplies the three things an agent needs: that it mutates state, the precondition, and the error outcome. Return-value detail is rightly left to the output schema.

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 100% and the single charger_id parameter is fully documented there, including its default resolution. The description adds no parameter-level meaning, so the baseline 3 applies.

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 ('pause') and resource ('the running charging session'), and even cites the underlying Zaptec command 506. The action is unambiguously distinct from siblings like zaptec_resume_charging, zaptec_get_status, or zaptec_set_available_current without needing their 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?

Clearly states the precondition for use ('only valid while the charger is in connected_charging') and the failure path ('otherwise returns an explanation'). It does not explicitly name an alternative tool or a when-not-to-use in terms of siblings, so it stops short of a 5.

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