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

Annotations already declare idempotentHint=true and destructiveHint=false. The description adds genuinely useful behavior beyond that: a timing precondition (resume_at) and a billing detail ('no extra credit is charged'). However, the cryptic term 'Silence' is never defined, weakening the disclosure.

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 short sentences, front-loaded with the action, with zero padding. The middle sentence is terse but its referent ('Silence') is opaque, which is a minor structure/clarity cost.

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 one-parameter mutation with no output schema and annotations covering the safety profile, the description covers the precondition and billing side effects adequately. It does not explain the 'Silence' concept or what state results from completion.

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 coverage is 0% for the single session_id parameter, but the name is self-describing (a UUID). The description partially compensates by implying an ownership requirement ('owned session'), which is a real authorization constraint beyond the schema, though it does not describe the id format.

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 ('Mark an owned session complete'), which is clear enough to distinguish from eclypse_start_session at a glance. It does not explicitly name or route away from any sibling, so it stops short of a 5.

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 precondition 'Silence cannot complete before resume_at' implies a timing constraint on when the call is valid, but there is no explicit when-to-use/when-not guidance and no named alternative. Usage is implied rather than stated.

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