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

Annotations already declare destructiveHint=true, idempotentHint=false, and readOnlyHint=false, so the safety profile is covered structurally. The description adds one genuinely useful behavioral fact — the required 'mcp:write' scope — but says nothing about the effect of flipping visibility (e.g., whether a public roster becomes discoverable), which is the main behavioral question for this tool.

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?

Two short sentences, front-loaded with the action and followed by the auth requirement. No filler, nothing redundant.

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?

Annotations cover the mutation/safety profile and there is no output schema to explain, so the bar is lower. Still, for a two-parameter mutation with zero schema description coverage, the definition leaves the parameter meaning and the practical effect of the change entirely to inference.

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 0%, so the description must carry parameter meaning, yet it never explains 'id' (roster identifier) or that 'visibility' takes one of private/unlisted/public. The schema's enum conveys the allowed values, but the description adds nothing about how the parameters map to the operation.

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?

The description gives a specific verb and resource ('changes the visibility of an owned roster'), which is clearly distinct from sibling tools like save_roster or get_my_roster. It stops short of naming how it relates to the surrounding roster tools, but the action itself is unambiguous.

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?

It scopes the tool to 'an owned roster,' which is a useful precondition, but there is no guidance on when to reach for this instead of save_roster or other roster siblings, and no mention of what happens when visibility is changed. Usage is implied only.

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