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

Annotations already declare destructiveHint=false and readOnlyHint=false, so safety profile is partly covered. The description adds material behavioral context beyond them: the effect persists across this study and later ones, undo is the escape hatch, and the call is free (implying other actions may cost). It does not discuss permissions or failure modes, but the persistence/reversibility disclosure is genuinely useful.

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?

Four terse sentences, consequence front-loaded, no filler. 'Free' is the only terse fragment and it earns its place by communicating 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 simple two-parameter, single-required write tool with no output schema, the description covers consequence, reversibility, and cost, and annotations cover safety. What is missing is minor: no error behavior or note on how to obtain the key (left to the schema).

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 key (IDEA:<slug>) and undo are already fully documented in the schema. The description's 'With undo, it comes back' reinforces the undo parameter's effect but adds little beyond the schema's own description. 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+resource and the concrete consequence: the founder will not build this idea and it is never offered again. An agent can tell it apart from ideas (which supplies the key) and from unrelated siblings, though the description never names a sibling to contrast against.

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?

Usage is implied by the framing ('the founder will not build this idea'), which tells the agent the condition under which skipping applies. However there is no explicit when-to-use/when-not guidance and no reference to alternatives such as ideas_run or the sibling *_skip tools for routing.

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