files_list_trending

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

Beyond annotations, it discloses the ranking mechanism ('activity signals rather than by the user's own history') and the scope ('around the signed-in user'). It also notes the API permission, adding useful behavioral context. No contradiction with the read-only, idempotent 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?

Three concise sentences: purpose, usage guidance, and permission. Every sentence has a distinct role without redundancies. Front-loaded with the primary action, making it easy to scan.

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 one optional parameter, no output schema, and strong annotations, the description covers all relevant aspects: purpose, ranking behavior, usage context, alternative, and permission. Nothing important is missing for an agent to decide when and how to use it.

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?

The schema already fully describes the single parameter (max_results with default and description). The description adds no additional parameter-level detail beyond what the schema provides, so the baseline of 3 is appropriate.

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: 'List documents currently trending around the signed-in user'. It specifies the ranking source ('Microsoft 365 activity signals') and explicitly distinguishes itself from the sibling tool files_list_recent.

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?

Provides an explicit use case ('what is the team working on') and names the alternative (files_list_recent) with a clear contrast ('what this user personally touched'). Also mentions the permission requirement, indicating when the tool is applicable.

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