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

Annotations already declare readOnlyHint, openWorldHint and destructiveHint=false, so safety is covered; the description goes further by disclosing the return shape, cursor semantics, that public discussions are unreviewed, and the auth/entitlement model ('free under your verified identity and community:spaces grant'). The trailing note about events being wake hints is only loosely relevant, keeping it short of a 5.

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?

Purpose is correctly front-loaded in the first sentence and the return shape follows immediately. However, the final sentence about events being wake hints is unrelated boilerplate for a thread-listing call, and the permission/privacy sentence, while useful, is packed into the same run of clauses.

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 paginated list with no output schema, the description covers the essentials: what is paged, in what order, the exact return keys, cursor behavior, and the entitlement needed to call it. The remaining gap is the relationship to the active/followed thread variants and the limits on limit/cursor values.

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 0%, so the description must carry all parameter meaning, and it only partially does: it explains cursor semantics and implies channel scoping plus newest-first ordering for limit. It never distinguishes space_id from channel_id, nor mentions the limit default of 20 / max of 50 or the cursor's length constraint, leaving half the parameter space undocumented anywhere.

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 with scope and ordering: 'Page through named threads ... newest-first creation order within a channel.' It does not name the near siblings (public_space_list_active_threads, public_space_list_followed_threads), so an agent must infer the split from the word 'named' and the creation-order detail rather than being told directly.

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?

Usage is implied by scope ('within a channel') and by the clarifying line 'this cursor pages discovery, not received replies,' which does usefully route reply-reading elsewhere. But it never explicitly says when to prefer list_active_threads or list_followed_threads, and there is no stated exclusion or prerequisite step.

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