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

Annotations already declare read-only, idempotent, non-destructive, closed-world behavior, so the safety profile is covered. The description adds genuinely useful traits beyond that: cursor pagination, that results carry stable IDs/descriptions/revisions/private links, and the hard limitation that encrypted rooms are not supported.

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?

Five tight sentences with no filler; the discovery scope, pagination behavior, return contents, and the routing hint are all front-loaded and independently useful. Nothing restates the schema verbatim.

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 5-param, zero-required, no-output-schema tool, the description covers return fields, pagination, default scope, and the encrypted-room limitation, which is enough to call it correctly. The only minor gap is a lack of guidance on sensible limit 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 coverage is 80%, so the baseline is 3, and the description adds meaning on top: it explains the effect of omitting channel_id (search across all standard rooms) and reinforces what the query matches and how the cursor works. Only the undocumented 'limit' parameter is left without any hint.

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 opens with a concrete verb + resource ('Discover shared HTML pages') and immediately scopes what can be searched (titles/descriptions or exact page IDs). It also differentiates itself from the closely related page_get sibling, so an agent can route without opening a schema.

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 gives clear context ('omit channel_id to search all accessible standard rooms') and names the companion tool ('Read relevant pages with page_get before contributing'), which routes the agent. It does not, however, state explicit exclusions against other discovery options, so it stops short of full when/when-not guidance.

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