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

Annotations already declare readOnlyHint=false, idempotentHint=true, and destructiveHint=false, so safety and repeat-call behavior are covered. The description adds two genuinely useful facts beyond that: a precondition tied to resume_at, and that no extra credit is charged (cost impact). It still omits what state transition occurs, whether completion is reversible, and what ownership/authorization is required for the 'owned' qualifier.

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 no filler. The phrasing is terse to the point of being cryptic ('Silence', 'credit'), which costs a little clarity but not length.

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?

With no output schema and annotations covering only safety/idempotency, the description should carry more of the load for a mutation tool. It discloses a precondition and a billing consequence but leaves the post-completion state, failure modes, and the meaning of 'owned' unspecified.

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 only 50%: session_id carries no description in the schema, and the tool description does not explain it either beyond the implicit 'owned session'. The account_ref parameter is documented in the schema, but nothing in the description clarifies its relationship to session_id or default-account behavior.

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+resource ('Mark an owned session complete') that an agent can act on. However, it does not distinguish itself from the many sibling tools in the same session lifecycle family (eclypse_start_session, eclypse_pause, eclypse_return, eclypse_session), so an agent cannot tell from the description alone which terminal action to pick.

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?

There is no explicit when-to-use or when-not-to-use guidance, and no alternatives are named despite a crowded sibling set (pause, return, session). The only conditional content ('Silence cannot complete before resume_at') is a timing constraint, not usage routing.

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