set_header

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

With no annotations present, the description carries the full behavioral disclosure burden. It discloses backup behavior (prev/anchor slots in .ks4w-backups), the subtle effect of backup=False ('skips rotation only'), atomic validated saving, and refusal to operate on documents open in Word. These are meaningful safety and edge-case details beyond the plain 'set' implication, though permissions and reversibility are not mentioned.

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?

The description is three compact sentences with the core action front-loaded before behavioral caveats. Every sentence adds information, and there is no filler. The phrase 'atomic validated save' is terse jargon but still earns its place by conveying data-integrity behavior.

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 mutating tool with no annotations and zero schema descriptions, the description delivers strong operational context around backups and Word-lock refusal. However, it leaves several parameters (section, alignment) and the effect on existing header variants unexplained. The presence of an output schema covers return-value shape, so the primary gaps are parameter semantics and alternative routing.

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?

The input schema has 0% property description coverage, so the description must compensate. It explains ref_type values and backup's semantic nuance, but leaves section, alignment, text, and file_path to be inferred from their names and defaults. This is only partial compensation for a schema that is entirely silent about parameter meanings.

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?

The description opens with 'Set a section's header text', naming a specific verb, resource, and scope. It also enumerates the ref_type variants (default|first|even), which clearly distinguishes header editing from footer or chapter-header operations. This separates it from siblings like set_footer and setup_chapter_headers without needing to read the 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?

There is no explicit guidance on when to use this tool instead of alternatives such as set_footer, get_headers_footers, or setup_chapter_headers. The only implicit signal is the header-specific wording and ref_type list, but no when-to-use or when-not-to-use conditions are provided. An agent must infer applicability from the name alone.

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