create_assignment

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

Annotations already declare readOnlyHint=false, destructiveHint=false, idempotentHint=false, and openWorldHint=true, so the safety profile is covered. The description adds the POST endpoint and the persistence effect of the marking, but says nothing about what happens if the assignment already exists (a real concern given idempotentHint=false) or about permission requirements for the access-restriction use case.

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 the action and resource, and the trailing sentence adds genuine explanatory value. There is mild redundancy between the title line, the bracketed endpoint, and 'Create a new tag assignment', but nothing harmful.

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 mutation tool with full parameter documentation, no output schema, and complete annotations, the core is present. Still missing are the duplicate-assignment behavior, any precondition that the tag/resource must exist, and whether the call returns the created assignment — reasonable gaps for an agent forming its first call.

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% — tagId, resourceId, resourceType, and x-trace-id are each documented, including the resourceType enum values in the description ('instance|image|object-storage'). The prose adds nothing beyond the schema, so the 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 ('Create a new assignment for the tag') and then explains what an assignment semantically does — marks a resource with a tag for organization or access restriction. That explanation meaningfully distinguishes it from create_tag and delete_assignment, though no sibling is named 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?

The phrase 'for organizing purposes or to restrict access to that resource' hints at two use cases, but there is no explicit when-to-use guidance, no prerequisites (the tag presumably must already exist), and no routing toward create_tag vs. create_assignment for an agent unsure which to call.

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