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

Annotations already declare readOnly, idempotent, non-destructive, closed-world behavior, so the bar is lower. The description still adds non-obvious behavior: cross-device projects are included and their deviceId identifies the primary device, filters affect mods/picks/totalMods but not goal availability, and pagination is required for more mods. It stops short of noting auth requirements or result ordering.

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?

Content is front-loaded: what is returned comes first, then identifier format, then filter scope, then pagination. Sentences are dense but each carries distinct information; the 'mod goalIds connect projects to features' clause is the one piece that reads as schema trivia an agent may not need upfront.

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?

An output schema exists, so return-value explanation is rightly omitted, and the cross-device caveat is genuinely valuable. Against nine parameters with only 33% schema coverage, though, the description leaves several filters (kind, limit, maxSetupMinutes, platform interaction) unexplained, and the nextOffset/offset naming mismatch could confuse a caller trying to paginate.

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 only 33%, so the description carries real weight. It explains the deviceId format (slug or 'device: ID') and the narrowing effect of goalId/mod filters on 'mods, picks and totalMods', which is useful. But kind, limit, maxSetupMinutes, and offset receive no explanation at all, and the mention of 'nextOffset' does not map cleanly onto the schema's 'offset' parameter.

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 specific verb and resource set: 'List a device's models, available and requested features, curated picks and public mods.' That is clearly distinct from sibling tools like get_mod, compare_mods, or get_my_devices. It does not explicitly name a sibling it replaces or is replaced by, which keeps it out of the top band.

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 operational guidance ('Accepts a device slug or device: ID', 'Pass nextOffset to see more mods') and clarifies filter scope ('goal availability remains catalog-wide'). However, it never says when to choose this over compare_mods, get_top_mods, or search, so the agent must infer the boundary itself.

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