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

Annotations already declare the mutation profile (readOnlyHint=false, destructiveHint=true, idempotentHint=true), so the bar is lower. The description adds what the structured data cannot: the required missions:write scope and config:write capability, the fact that null clears an existing value, and the dependency of supersededBy on superseded. It does not describe concurrency or overwrite-warning behavior beyond the clear semantics.

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?

A single dense but well-ordered passage: purpose first, then the value taxonomy, then the correction case, then the behavioral constraint and permissions. Every clause carries information, though the parenthetical explanations could be tightened slightly.

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 three-parameter mutation with no output schema, this covers purpose, allowed values, conditional parameters, clearing semantics, the human-answer constraint, and required scopes. Only the side effects on delivery statistics (mentioned as consuming the value but not how) remain unspecified, which is a minor omission.

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 100%, so the baseline is 3, but the description genuinely adds meaning beyond the schema: it explains the semantic intent of each enum value (real work judged on merits, a deliberate test, replaced by another mission, finished outside SHIP) and restates that supersededBy is conditional. The issueId format is left to the schema, which handles it well.

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 — recording a person's reason for why a mission ended — and then enumerates the exact vocabulary (product, probe, superseded, takeover, null) plus what each means. This is unambiguous and clearly separable from siblings like archive_mission, stop_mission or set_mission_auto_merge, which touch lifecycle state rather than delivery disposition.

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?

Gives explicit when and when-not guidance: 'Set it only with the person's answer, never from your own guess' rules out speculative invocation, and it flags that supersededBy applies to superseded only and that null is for correcting a mistake. No sibling alternative is named for the case where the disposition is unknown, which is the only gap.

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