save_workbook

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

Despite annotations being minimal, the description extensively discloses behavior: default path (opened from or last saved), what is saved (values, formulas, block structure), the BLOCKREF issue and one-way resolution, and the result carrying a link instead of bytes. This goes far beyond the annotations and provides critical behavioral context.

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 somewhat long but well-structured: purpose first, then defaults, then a critical warning about block refs, and result behavior. Every sentence contributes necessary information, but the length could be trimmed if some details were in schema or annotations. No wasted words, but not maximally concise.

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 save operation with no output schema, the description covers all important aspects: destination, what data is persisted, Excel compatibility nuances, one-way export, and return format (link). It also implies the tool's role in the overall workflow. This is comprehensive for its complexity.

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% with both parameters described, but the description adds meaningful context: path defaults and when to set resolve_block_refs (Excel vs round-trip, one-way nature). This goes beyond the schema, so it earns above the baseline 3, though it doesn't introduce new parameter syntax.

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 clearly states the tool writes a workbook to a real .xlsx file for the human to open. It distinguishes from sibling tools by emphasizing 'real .xlsx file' and 'hand your work back', but does not explicitly differentiate from export_xlsx, so it lacks explicit sibling differentiation. Thus, it's clear but not fully distinguishing.

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?

It explicitly states when to use the tool ('do it when the task is done') and provides detailed guidance on when to set resolve_block_refs (for Excel vs round-trip). However, it does not mention when not to use it or alternatives like export_xlsx, so it lacks exclusions. This is clear context but with no explicit alternatives.

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