get_register

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

With no annotations present, the description carries the full load and does so well on the critical point: 'Documentation only; never touches a device' is an unambiguous no-side-effect guarantee. It also discloses the substance of the payload (write_function 0x06 vs 0x06/0x10, persistence classes, confirm_by registers), though it says nothing about behavior when an address is invalid or ambiguous.

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 purpose, then a dense but purposeful field inventory, closing with the safety constraint. The long middle clause is verbose but every listed field answers 'what will I get back' for a tool with no output schema, so little 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?

No output schema exists, so the description must describe returns — and it does so thoroughly, covering both plain registers and SunSpec addresses. The gaps are behavioral rather than informational: no guidance on invalid/unknown addresses or on routing to sibling tools.

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 address parameter already documents all three accepted forms (numeric, native name, SunSpec point), so the description adds nothing parameter-specific. Baseline 3 applies since the schema does the work.

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 ('Full documentation of one register') and immediately enumerates the returned documentation fields, so an agent knows exactly what kind of payload to expect. It does not explicitly name search_registers or get_sunspec_point as the alternatives, so differentiation from siblings is only implied by the singular 'one register' framing.

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 closing line 'Documentation only; never touches a device' hints at when this is appropriate (pre-write inspection), but there is no explicit guidance on when to pick this over search_registers for lookup or get_sunspec_point for SunSpec details. Usage must be inferred entirely from the field enumeration.

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