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

Goes well beyond the annotations (which only declare readOnlyHint=false, idempotentHint=false, destructiveHint=false, openWorldHint=false). It discloses the required permission (project.content.create, CONTRIBUTOR+, Viewers read-only), the 100KB UTF-8 cap, the prerequisite that libraryId must reference an existing library, and a detailed supported/unsupported markdown feature list.

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?

Front-loaded with the core action and use case before diving into prerequisites, limits, and the markdown feature list. The feature enumeration is long but each item prevents a real failure mode (e.g. images degrading to alt text), so it mostly earns its place, though it could be tightened.

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?

With no output schema, the description covers the important operational facts: permissions, size limit, prerequisite library, and content format constraints, plus what the operator does with the result. It omits any mention of what the call returns (e.g. document id), which an agent invoking this might benefit from knowing.

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 67%, so the schema already documents title length and the contentMarkdown 100KB cap. The description compensates by adding the libraryId existence requirement and the create_library prerequisite, plus rich content-format semantics (supported markdown features and degradations). It does not add anything about the title parameter beyond the schema.

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 ('Draft a markdown document directly into a project document library as a first-class file, mimeType=text/markdown') and clarifies the intended use case (status reports, summaries, prose deliverables). It differentiates from the file-upload sibling by naming the alternative route for oversized content.

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?

Gives clear context ('Use for status reports, summaries, and other prose deliverables the team reviews in context') and names alternatives: create_library when the library is missing, and the file-upload route for content over 100KB. It does not explicitly contrast with other document-creation siblings like create_page, create_wiki_page, or create_office_document, leaving some routing ambiguity.

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