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

Annotations already declare readOnlyHint=true, destructiveHint=false, and idempotentHint=true, so the safety profile is covered. The description adds useful behavioral context: it explains the refusal rule for posts and that the tool shows member states and reconnection counts. This goes beyond what annotations provide, though it doesn't discuss pagination or output format (covered by output schema).

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 two sentences and packs in purpose, content, and usage guidance without fluff. However, the opening phrase 'Your named sets of accounts' is a bit vague and could be more direct (e.g., 'Lists all account groups'). It's efficient but not perfectly front-loaded.

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 listing tool with no parameters and an output schema, the description is complete. It explains the tool's purpose, what the output contains, and a practical use case. The presence of an output schema covers return format, so nothing essential is missing.

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 tool has zero parameters, so the schema coverage is trivially 100%. The baseline for 0 params is 4. The description correctly implies no inputs are needed and explains what the tool returns, but it doesn't add parameter-specific semantics since there are none to explain.

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 lists account groups and explains what each group contains (members, states, reconnection count). It gives a specific reason for using it (check before posting) which distinguishes it from group mutation tools like groups_create/update/delete. The verb 'list' and resource 'account groups' are explicit, and the description is not a tautology.

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 explicitly says to check here before composing a post because a post naming a group is refused if any member cannot publish. It also recommends using a group name with posts_schedule instead of listing account ids, which points to an alternative workflow. This gives clear when-to-use and when-not-to-use guidance.

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