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

Goes well beyond the annotations: it discloses partial-failure semantics (out-of-reach ids are skipped and counted as `skipped`, never fatal), that existing membership is preserved, that no content/settings/location change, and the required permission. The annotations only carry the safety profile; the description supplies the rich behavioral detail.

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, then behavioral guarantees, then alternatives, then permission. Every sentence carries distinct information; there is no filler despite the density.

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 spelled out, yet the description still summarizes the return (count and ids). Combined with the safety annotations and full schema coverage, an agent has everything needed to call this correctly.

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%, so both groupId and screenIds are fully documented in the schema (including the sgrp_ prefix and the 1–5000 bound). The description adds the 'existing group' precondition but no new syntax or format detail, 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+resource ('Add screens to an existing screen group') with clear scope, and explicitly names the sibling operations it is not (create_screen_group, remove_screens_from_group, assign_screen_to_node). An agent can distinguish it from all three without opening any schema.

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?

Gives explicit routing: create_screen_group for a new group, remove_screens_from_group to remove, assign_screen_to_node to move location. It also states the prerequisite permission ('Requires `screen.edit`'), leaving nothing to inference.

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