delete_session_variable

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

Annotations already reveal the operation is mutating (readOnlyHint=false) and idempotent (idempotentHint=true). The description adds the 'user-defined' scope, which is useful, but it does not disclose effects on session history, behavior when the variable does not exist, or whether deletion also clears related context. No contradiction with annotations is present.

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?

The description is one direct sentence with no filler or repetition. The core action and target resource are front-loaded, making it immediately scannable for an agent.

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?

This is a low-complexity tool with one well-documented parameter and annotations covering idempotency and mutability. The description and schema together are sufficient to invoke it correctly. A minor gap is the lack of any mention of behavior for nonexistent variables, but idempotency hint partially covers that.

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?

The schema fully documents the single parameter with 'Variable name to delete,' so schema description coverage is 100%. The description adds no further parameter-level detail beyond 'user-defined,' so it meets the baseline but does not exceed the schema's contribution.

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 uses a specific verb and resource: 'Delete a user-defined session variable.' It also adds scope with 'user-defined,' which distinguishes it from system-level session state and from sibling tools like set_session_variable, get_session_variable, and clear_session_context.

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 description implies this tool should be used when a user-defined session variable is no longer needed, but it does not explicitly state when to prefer this over clear_session_context or list_session_history, nor does it mention any conditions or exclusions. Usage guidance is present only by inference.

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