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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=true, so the safety profile is conveyed by structured fields. The description adds only an enumeration of returned fields, which the output schema already covers, and says nothing about result volume, pagination, or how the optional apis filter narrows the set.

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?

A single front-loaded sentence with no filler or redundancy. Brevity costs it here, since the space saved went toward under-specification rather than efficiency, but the sentence itself is clean and well-ordered.

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 values need not be explained, but an unfiltered list tool with a default limit of 200 and an undocumented apis filter leaves the agent unable to reason about scope or pagination. Nothing routes it against skills_search or skills_read, which is essential given three overlapping skill tools.

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 description coverage is 0% for two parameters, so the description is the only possible source of meaning, and it provides none: "APIs" appears to describe a returned field rather than the apis filter argument and says nothing about limit's default of 200. This is a genuine gap, but the description's field enumeration indirectly tells the agent what the apis filter ranges over, keeping it from a bottom score.

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 gives a clear verb + resource ("List Learnosity integration skills") and names the returned fields (ids, titles, goals, APIs), so an agent knows exactly what the tool produces. It falls short of a 5 because it never distinguishes the tool from its siblings skills_search and skills_read, which sound like competing ways to reach the same skill data.

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?

There is no guidance on when to use this tool versus skills_search or skills_read, despite both being listed siblings operating on the same resource. The description also doesn't say when a listing is preferable to a targeted lookup or search, or what happens if the result set is large.

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