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

Adds significant behavioral context beyond annotations: it discloses that hosts that re-read the tool list will show new tools, while connect-time hosts like ChatGPT will not, and that the tool reports this instead of returning a misleading success. It also states it is free, instant, and never turns anything off, which is not evident from the annotations alone.

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 long, but nearly every sentence carries actionable information: trigger conditions, host caveat, default roster, held-out groups, and accepted values. It is front-loaded with the core action and expands only where it directly affects invocation.

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 meta-configuration tool with no output schema and one parameter, the description is complete: it lists valid groups, explains the default and excluded groups, provides concrete trigger examples, covers the host-dependent limitation, and gives the fallback connection-time route. No meaningful gap remains for correct selection and invocation.

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?

Though the schema already documents the single 'groups' parameter, the description enriches it with the full list of accepted groups ('core, research, create, channels, channel_admin, analytics, ads, files, workspace — or all'), the default roster, and the held-out groups. This gives an agent everything needed to construct correct calls.

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 ('Switch on a group of tools') and clearly distinguishes itself from the fixed roster and other tools by explaining it affects the session's tool list. The contrast with the `?tools=all` connect-time route helps an agent understand exactly what this tool is for.

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 explicit when-to-use instructions: 'CALL THIS THE MOMENT YOU NEED ONE' with concrete examples for ads and analytics. It also names the alternative ('?tools=all') for hosts that fix their roster at connect time, and explains when that route should be preferred.

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