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

Annotations already declare destructiveHint=false and idempotentHint=true; the description adds genuinely new behavior context: 'direction-normalized' (link order doesn't matter) and the same-project precondition for design and work item. It does not describe failure modes (e.g. cross-project rejection) or the response shape, but it goes beyond the annotation 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?

Four short sentences, front-loaded with the action and target types, then the important negative constraint, then idempotency and the project precondition. No filler; each sentence carries information an agent needs.

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 3-param mutation with full schema coverage and annotations covering safety, the description supplies preconditions and idempotency, which is nearly everything needed. Minor gap: no mention of what happens on precondition failure or what the call returns, though no output schema exists to rely on.

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 the three parameters are already documented, and the baseline would be 3. The description still adds a real constraint on designId/issueId — both must resolve within the same project — and frames the issueType enum targets, which is meaningful semantics not encoded in 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?

Names a specific verb+resource pair ('Link an existing UI design') and enumerates the exact targets (story, defect, epic) plus the underlying 'has_design' relationship. This clearly separates it from sibling write tools like stride.link_diagram and stride.generate_ui_design.

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?

Gives a clear usage context (linking an already-existing design, not creating one) and an explicit exclusion: it does not render or attach a PNG, and the in-app studio should be used for that. It stops short of naming sibling tools (e.g. link_diagram, generate_ui_design) as alternatives, so routing is implied rather than explicit.

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