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

Annotations already carry the safety profile (readOnlyHint=false, destructiveHint=true), so the bar is lower. The description adds meaningful beyond-schema context: the atomic all-or-nothing guarantee of the batch, the explicit warning about 'index calculation errors,' and the phased-workflow strategy to avoid them. It doesn't cover rate limits or failure-mode details, but the atomicity and index-hazard disclosure are genuinely additive.

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 long, but the tool is genuinely complex (25+ operation types), and each section earns its place: purpose, sibling routing, then a structured workflow with a concrete example. The example batch is verbose but high-value, since it demonstrates the exact operation-dict format. Purpose and routing are front-loaded, though the workflow section could be tightened slightly.

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?

The output schema exists, so return values need no explanation; annotations cover the safety profile. For a tool of this complexity, the description addresses the single most dangerous failure mode (index calculation errors) with a prescriptive workflow. It does not explicitly compare against other doc-mutation siblings like insert_doc_elements or modify_doc_text, which would round it out, but the critical-path guidance is complete.

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 the baseline is 3. The description adds value beyond the schema by explaining how to use the most error-prone parameter (operations): the end_of_segment=true pattern, a concrete example batch showing the exact operation-dict shape, and guidance on when index math is needed versus avoided. This operational meaning complements the schema's per-field documentation rather than repeating it.

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 opening sentence states a specific verb ('Executes'), resource ('low-level document operations'), and scope ('single atomic batch update') that distinguishes it from the single-operation doc tools in its sibling set. The emphasis on 'multiple' and 'low-level' clearly separates it from higher-level tools like update_doc_headers_footers and modify_doc_text.

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?

Explicit routing guidance names the alternative tool and the condition that selects it: 'For normal header/footer text, prefer update_doc_headers_footers' and 'Only use create_header_footer here for advanced section-break layouts.' The RECOMMENDED WORKFLOW section further tells the agent exactly when and how to use this tool (phase-based building with end_of_segment=true) versus other approaches.

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