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

Annotations already declare idempotentHint=true and destructiveHint=false, so repeating "Idempotent" adds little; however the description contributes genuinely new behavior: the same-project constraint and the downstream effect that the diagram surfaces in the get_story_context bundle under `diagrams`. It doesn't say what happens on a cross-project attempt (error vs silently rejected), which keeps it off a 5.

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?

Three short sentences, front-loaded with the action, then the relationship name, then the side-effect and constraint. Nothing is padding and each sentence carries a distinct fact.

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 three-required-param mutation with no output schema, the description covers the key facts an agent needs: what gets created, that it's idempotent, the cross-project restriction, and where the result becomes visible. Only the failure mode for mismatched projects is left unspecified.

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 enum for issueType is documented inline, so the schema already carries full parameter meaning. The description adds no per-parameter detail (e.g., whether diagramId must be an existing generated diagram vs any diagram) beyond what the schema states, 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 (Link) plus the resource (an existing architecture diagram) and the target (story, defect, or epic), and names the canonical "has_diagram" relationship. That relationship name distinguishes it from the generic stride.create_cross_link and from stride.link_design without the agent opening any schema.

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?

"Link an existing architecture diagram" plus the same-project precondition gives a clear context for use, and the get_story_context consequence tells the agent why it matters. It stops short of explicitly excluding the sibling alternatives (create_cross_link, link_design), so an agent comparing those tools still has to infer the boundary.

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