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

Annotations already establish the non-read-only, non-destructive, non-idempotent profile, so the bar is lower. The description still adds real behavior: the file lands in the Documents tab and can be co-edited in the in-browser Office editor, and it requires the project.content.create permission (CONTRIBUTOR+, Viewers read-only). It does not touch duplicate-name or repeat-call behavior, so a 4 rather than 5.

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 verb+resource is front-loaded, followed by the alternative-routing rule, format aliases, prerequisite, and permission note. Five dense sentences, each of which carries distinct information with no filler.

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?

There is no output schema, yet the description still tells the agent what gets created, where it appears, how it will be edited, what permissions are needed, and which sibling to use instead. For a creation tool with three simple parameters, nothing an agent needs is missing.

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%, so the enum aliases and the name default are already documented, giving a baseline of 3. The description goes slightly beyond the schema by spelling out that libraryId must reference an existing library and how to obtain one via create_library, adding actionable meaning.

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 ('Create a blank, editable Office document') and enumerates the three formats, so the agent knows exactly what is produced. It also distinguishes itself from the sibling draft_document by noting that the latter only makes markdown.

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?

Explicitly says when to use this versus the alternative ('Use this (not draft_document...) when the deliverable should be a real Office file the team will edit'), and adds the prerequisite for libraryId ('create one first via create_library if needed'). Nothing about routing is left to inference.

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