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

Annotations already cover read-only, idempotent, closed-world, non-destructive, so the description's job is to add context — which it does: capped at the most recent 24, not paginated, and empty when the site's `screenshots_disabled` flag is true. That last condition is genuinely useful behavior an agent cannot get from annotations. Only missing piece is ordering metadata (per-item fields) for callers.

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?

Three short sentences, zero padding, with the core identity front-loaded and the constraints (limit of 24, no pagination, empty condition) immediately after. 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?

With no output schema, the description usefully describes the return set: screenshots from the surf session, most recent up to 24, unpaginated, possibly empty. That's sufficient for a simple list tool, though the shape of each returned screenshot is left unstated.

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?

Single `id` parameter with 100% schema description coverage ('Site identifier.'), so the schema does the heavy lifting and baseline 3 applies. The description only restates that it is 'a site's' screenshots and adds no format or sourcing detail about the id.

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?

Specific verb ('List') plus a precisely scoped resource ('a site's FeelingSurfViewer screenshots'), with the second sentence clarifying what those screenshots actually are (captures taken while the app surfed the site). An agent can immediately distinguish it from the singular get_screenshot sibling.

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 the name and scope — listing all screenshots for a site versus fetching one via get_screenshot — but the description never states when to prefer this over get_screenshot or list_surf_sessions, and offers no exclusions or prerequisites beyond the empty-list note.

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