set_text_decoration

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

No annotations are provided, so the description carries the load. It usefully discloses that it reports per-node success, supports instance-nested text via 'I<instanceId>;<textId>' syntax, and allows an optional char range, but says nothing about permissions, reversibility, or behavior on non-text nodes — significant for a mutation tool with zero annotation coverage.

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?

A single compact sentence that front-loads the operation and packs scope, instance handling, range, and return behavior without waste.

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 no-output-schema mutation tool it covers node types, instance addressing, character-range scoping, and per-node result reporting. Gaps around permissions and error/reversibility behavior keep it from a 5.

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 100% (baseline 3), and the description adds value beyond the schema by explaining the instance text-node ID format and the [start, end) half-open range semantics that the schema properties only hint at.

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 (set underline/strikethrough/none on TEXT nodes) and clarifies it works on text inside instances. Clear purpose, though it doesn't explicitly distinguish itself from siblings like set_text_content or update_text_style.

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 is implied by the description (optionally apply to a character range) but there is no explicit when-to-use guidance, no prerequisites, and no indication of when to prefer this over set_text_content or apply_text_style.

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