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

Annotations already declare destructiveHint=true and idempotentHint=true, so the safety profile is covered. The description still adds real value beyond them: it specifies what is destroyed ('stored state, including the record itself') and the lease-refusal/force behavior, which annotations cannot express.

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?

Three sentences, all load-bearing: the core action and its scope, the sibling routing, then the idempotency and refusal semantics. Front-loaded with the verb and no filler.

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?

A destructive mutation with no output schema and full annotation coverage needs precisely this: what gets destroyed, what happens on repeat calls, and the prerequisite for success. All present, so an agent can call it correctly without further context.

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 100%, so both parameters (session_id, force) are already documented in the schema, including what force does. The description references force's effect ('unless force is true') but adds no syntax or format detail beyond the schema. Baseline 3 is appropriate.

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 resource (session and its stored state, including the record itself), and explicitly contrasts with the sibling spicrawl_session_release. An agent can distinguish it from release/get/list without opening any schema.

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?

Names the alternative (spicrawl_session_release) with the exact selecting condition ('if you only want to stop using it'), and states the guard condition for refusal (active lease) plus the escape hatch (force). Nothing is left to inference.

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