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

Beyond the annotations it discloses what each call shape returns (index of IDs/titles/summaries vs. complete guides with usage notes) and that results preserve request order. The closing 'server marks it read-only, so it runs straight away' sentence largely restates readOnlyHint/idempotentHint rather than adding new information, which keeps it out of the top band.

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?

Four short sentences, front-loaded with purpose and followed by return behavior, scope limits, and safety. The 'Through Royally' sentence is filler relative to the annotations and could be dropped without losing meaning.

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?

There is no output schema, and the description adequately explains both return modes and the curated-library limitation. An agent can call it correctly on the first try; only the absence of explicit sibling routing keeps it from a 5.

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 100%, so both parameters are already documented, including the 'omitting topics returns the index' and 'empty array is invalid' constraints. The description echoes that behavior but adds no format or ordering nuance beyond the schema, so the baseline 3 applies.

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 uses a specific verb+resource ('Provides guides') and enumerates the covered topics (selecting a site, Jetpack connection, creating content, account preferences). It also carves out scope by stating it 'does not list every available capability or search site content', which implicitly separates it from the search/describe siblings, though it never names an alternative tool directly.

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 a concrete two-step workflow: empty arguments return the topic index, selected topics return full guides. The negative guidance ('does not list every available capability or search site content') signals when-not-to-use. It stops short of naming the sibling tool an agent should call instead when it needs a capability listing or content search.

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