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

With no annotations the description carries the full load and does disclose meaningful traits: the operation is idempotent, scope is resolved from the X-Project-Scope header then SCOPE_DEFAULT, 'global' forces a NULL scope, and global memory is only readable with Pro. It still doesn't say what happens to data outside the targeted (persona, scope) pair.

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-loads the action and the idempotency guarantee, then explains the scope parameter. Dense but every sentence carries operational content; the trailing policy remark about where project facts belong is the only slightly padded part.

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 purge tool with an output schema and no annotations, the description covers idempotency, scope resolution, and the Pro gating on global memory. The main omission is any statement of required permissions or the blast radius of the purge outside the targeted couple.

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 compensate, and it does for project_scope: omission semantics, the header fallback chain, and the 'global' sentinel value are all explained. persona_slug is left to its name and 'soov' default without further meaning.

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 — clearing the previous-context for the (persona, scope) pair — which an agent can distinguish from the sibling write_previous_context. It never names that sibling explicitly, so the contrast relies on the verb alone.

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 real guidance on which scope value to choose (project scope by default; 'global' only for cross-project facts), but says nothing about when to purge versus write or read memory, and no sibling tool is named as an alternative. Usage is implied rather than routed.

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