run_decay

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

Goes well beyond the destructiveHint/not-idempotent annotations: it discloses that MUST memories are exempt, that the operation is not purely reversible, and exactly when it becomes permanently destructive (MEMVAULT_FORGET_AUTO_ENABLED=1 with the default 90-day retention). The auth requirement and the enumerated return counts are also stated.

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?

Front-loaded with the core action and mechanism, then the risk caveat, then auth, then return shape — a sensible order. All four sentences carry information; the parenthetical env-var detail is dense but load-bearing rather than 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?

For a destructive tool with no output schema, the description covers the mutation semantics, exemption rules, conditional irreversibility, auth prerequisites, and the shape of the return counts. An agent has everything needed to decide and call it correctly.

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 api_key and agent_id are already documented; baseline is 3. The description adds value by explaining when api_key is actually required ('when the agent has a registered key'), giving an agent a decision rule the schema only hints at.

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 ('Run a memory decay cycle') and immediately explains the mechanism: lowering decay_score for old memories and archiving those below threshold. This is distinguishable from siblings like run_dedup, run_promote, or forget_memory because the decay/archive semantics are unique to it.

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 conditions that select this tool are clear from the description of the cycle, and the exemption rule for MUST memories is spelled out. It does not explicitly say 'use forget_memory instead when...' or name alternatives, so it stops short of full routing guidance.

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