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

Annotations already declare destructiveHint=true and idempotentHint=true, so safety is covered structurally; the description adds value by making the destruction scope concrete (sessions AND trigger memory) and emphasizing 'Irreversible' and 'Permanently', which are stronger claims than the generic destructive hint.

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 operation and its irreversibility; no filler or redundancy.

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 destructive one-parameter tool with annotations covering safety and no output schema, the description supplies the essential scope and irreversibility warnings. It omits edge-case behavior (e.g., deleting a nonexistent subject) and auth requirements, keeping it from a 5.

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% for the single subject_id parameter, and the description does not explain what a subject_id is, where to obtain it, or its format. The name is largely self-evident, so this is not fatal, but the description adds no semantic detail beyond 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?

States a specific verb (delete) plus the exact scope of the resource destroyed (all sessions and trigger memory for a subject), which an agent cannot confuse with the read-only siblings get_session_history or get_trigger_memory.

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?

'Only call when the user explicitly requests this deletion' gives an explicit precondition, which is the key gating rule for a destructive tool. It does not name an alternative tool or describe what to do otherwise, so it falls just short of a 5.

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