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

Annotations already cover the safety profile (readOnly, non-destructive, openWorld=false), and the description adds genuinely useful behavior: no account required, and cursor-based pagination via the returned `nextCursor`. It could say more about ordering of results or result caps, but it is well above the annotation baseline.

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?

Front-loaded with purpose and the "call it first" directive, then parameter hints, then return shape. The list of result fields is a long run-on clause, but it is informative rather than filler.

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 zero-required-parameter search with an output schema and read-only annotations, the description covers purpose, timing, parameter edge cases, and pagination. The enumeration of return fields is partly redundant with the output schema, but nothing an agent needs to invoke it correctly is missing.

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?

With 75% schema coverage the schema does most of the work, but the description adds semantics the schema lacks: an empty `q` means "newest" rather than an error, and `site` is illustrated as a bare host like youtube.com. `limit` is left entirely to the schema.

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?

"Search the public jigs other people published" names a specific verb (search), a specific resource (jigs), and a scope qualifier (public, other people's) that separates it from jig_list, jig_get, or jig_read. The parenthetical example query makes the intended use concrete.

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?

"Call it BEFORE building a page from scratch" gives a clear trigger condition, and the empty-`q` and `site` clauses explain the two common invocation modes. It does not name an alternative sibling (e.g. jig_list vs jig_search) or state when not to use it, so it falls short of a 5.

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