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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so "Read-only; changes nothing" largely restates structured data. The one genuinely additive note is "Money is integer minor units (cents)," which discloses a data-format trait not captured by annotations.

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, front-loaded sentences with no padding. The money-format sentence is slightly tangential to a plugin catalogue but still earns its place as a data-format warning.

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, zero-parameter tool the description is close to sufficient, but it omits the catalogue's return content and the free/paid install routing, both of which sit in the schema description rather than the tool description. With no output schema, the description should carry more of that load.

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?

The tool takes zero parameters, so the baseline of 4 applies. There is no parameter surface for the description to clarify, and the empty schema is self-explanatory.

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?

"Plugins the shop can add" names the resource (available/installable plugins) but is a bare noun phrase with no verb and no explicit contrast against the sibling plugins_list. An agent could infer this is the catalogue vs. installed plugins, but the description itself does not make that 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 guidance and no alternatives named in the description. The routing hint (free plugins install via plugins.install, paid ones on the Plugins screen) lives only in the input schema's description field, not the tool description, so the description offers no selection help against plugins_install or plugins_list.

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