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

Annotations already declare readOnlyHint=true, so safety is covered. The description adds that it is the files.list surface and enumerates the filter axes, but says nothing about pagination behavior or result shape. With annotations carrying the safety profile, this is adequate but not rich.

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?

Two compact sentences: purpose and filter scope front-loaded, then the follow-up routing. No filler or redundancy.

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 read-only list tool with full param coverage and an annotation declaring its safety profile, the description covers purpose, filtering, and next steps adequately. The absence of an output schema means return shape is unexplained, but this is minor for a listing tool.

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 description coverage is 100%, so all eight parameters are documented in the schema itself. The description summarizes the filter dimensions (channel, user, type, time window), which mirrors rather than extends the schema. Baseline 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 states a specific verb and resource ('List files shared in this Slack workspace') and even names the underlying API call (files.list). It implicitly separates itself from read_slack_file and manage_slack_files by positioning those as downstream consumers of the returned ids.

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 tells the agent what to do with the result ('Use the returned file ids with manage_slack_files or read_slack_file'), giving strong context for the discovery-then-act flow. It lacks an explicit when-not-to-use clause or a named alternative for other listing needs, so it stops 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.