files_get_group_drive

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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint false. The description adds valuable context beyond annotations by specifying required permissions (Files.Read.All and Group.Read.All), the exact return values (drive id and web URL), and the tool's role as a prerequisite for other file tools. No contradictions with annotations.

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 sentences, front-loaded with the core action, and every sentence earns its place: what it does, what it returns and why, and required permissions. No redundant or extraneous information.

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 compensates by explaining the return values (drive id and web URL) and their purpose. It also covers prerequisites (group id from directory_search_groups), permissions, and the relationship to other file tools. For a single-parameter tool, this 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 coverage is 100% with group_id described as 'Microsoft 365 group (Team) id — same as team.id.' The description enhances this by specifying the source: 'given a group id from directory_search_groups,' which tells the agent where to obtain the value. This adds meaningful context 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?

The description clearly states the tool's function: 'Get the document library backing a Microsoft 365 group or Teams team.' It specifies the resource (document library) and the action (get), and distinguishes itself from sibling file tools by noting it returns the drive id and web URL needed by other file tools.

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?

The description provides clear usage context: it takes a group id from directory_search_groups and explains that the returned drive id and web URL are prerequisites for other file tools. It implies when to use (before reading/writing in a team's files) but does not explicitly state alternatives or exclusions, so it falls short of a 5.

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