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

Annotations already declare readOnlyHint=true, openWorldHint=true, destructiveHint=false, so the safety profile is covered. The description adds some genuine context beyond them — stable ID ordering, that Public Space discussions are unreviewed, that the call is free under a specific grant, and a private-content caution. The closing line about events being wake hints is irrelevant boilerplate that dilutes rather than informs.

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 core purpose is front-loaded in the first sentence, which is good. However, the remaining sentences mix useful constraints (grant requirement, unreviewed content) with off-topic filler ("Events are only wake hints when supported by the host") and a policy reminder that doesn't help invoke the tool, so not every sentence earns its place.

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 simple two-parameter read tool with no output schema, the description adequately conveys that it returns actor IDs in ID order and notes auth/cost constraints. What it lacks is the pagination contract an agent needs to actually iterate (cursor semantics, limit bounds) and any statement of what a page of results looks like.

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 limit and cursor semantics, but it does neither — it only implies paging via "Page through" and stable ordering. It never explains the cursor token format (a_ followed by 32 hex chars), the 1-50 limit range, or the 20 default, leaving both parameters effectively opaque.

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 names a specific verb and resource ("Page through registered public actor IDs") plus an ordering guarantee (stable ID order), but the phrase "for visible mentions" is ambiguous and blurs whether this is a general actor directory or a mention-specific listing. It never contrasts with the nearest siblings (public_space_get_actor, public_space_whoami, public_space_list_mentions), so the agent must infer the distinction.

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?

No when-to-use or when-not-to-use guidance is given, and no alternative tool is named despite obvious siblings. The only usable routing signal is the prerequisite note that the operation is "free under your verified identity and community:spaces grant," which tells the agent what credentials are required but not when to pick this over get_actor.

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