Get Ravelry yarn details

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

Annotations already declare readOnlyHint, idempotentHint, and openWorldHint, so the safety profile is fully covered externally. The description adds nothing behavioral beyond that (no rate limits, auth needs, or partial-failure behavior), and its field list largely restates what the existing output schema already conveys.

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 wasted preamble; the enumerations of returned attributes are dense but relevant. Slightly long in the tail, but appropriately sized for the tool's scope.

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?

With annotations covering safety, a 100%-covered single-parameter schema, and an output schema handling return structure, the definition is nearly self-sufficient. The only omission is any guidance on when this is the right lookup versus searching, which keeps it short of 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 description coverage is 100% and the single parameter already documents the 1-to-20 id range and integer type. The description only echoes 'by id', adding no format, ordering, or error-handling semantics beyond the schema, so 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?

States a specific verb and resource ('Get full details for one or more yarns by id') and the 'by id' qualifier cleanly separates it from sibling search_yarns / find_yarns_for_pattern, which operate by query or pattern. The listed attributes further pin down exactly what 'full details' means.

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?

The 'by id' phrasing implies this is a follow-up to a search (you need an id first), but the description never states when to prefer this over search_yarns or match_yarns, nor any prerequisites. Usage is only implied, not explicit.

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