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

No annotations are supplied, so the description carries the full behavioral burden. It does disclose one useful behavioral fact — that the response includes sub-skills — but says nothing about behavior for an unknown id (error vs. empty), whether the lookup is exact-match or case-sensitive, or whether results are cached.

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 the core action first, the key format second, and the sub-skill note last. Nothing is redundant and the example is load-bearing rather than padding.

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 single-parameter read lookup with no output schema, the description covers the essential call contract and hints at the payload shape ("with its sub-skills"). Minor gap: without an output schema, a brief note on what a skill record or the sub-skills list looks like would fully close the loop.

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%, so the description must compensate for the single skill_id parameter. It does so meaningfully by giving a concrete standards-id example (CCSS.MATH.4.NF.A.1), which conveys the expected format, but it omits whether other identifier schemes are accepted or how strictly the format is validated.

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 specific verb and resource ("Get one skill") and constrains the lookup key to a standards id, with a concrete example. It implicitly contrasts with the sibling list_skills by emphasizing "one skill," though it never names that sibling explicitly.

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 only implied: an agent can infer this is for fetching a single known skill rather than browsing, but the description states no when-to-use condition, no alternative (e.g. list_skills for discovery), and no prerequisite about where a standards id comes from.

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