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

Annotations already declare destructiveHint=false and idempotentHint=true, so safety is covered; the description adds genuine state-change context (removal from the planning order, move to the declined list) and the important non-idempotent side effect that re-declining overwrites the existing reason. It doesn't mention recoverability, though restore_idea exists as a sibling.

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 tight sentences with the core action front-loaded and the edge-case behavior last. No filler, though the middle sentence about planning order could be folded into the first without loss.

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?

No output schema exists, and the description adequately conveys the resulting state (removed from planning order, listed as declined) plus the overwrite semantics. For a two-parameter mutation with annotations covering the safety profile, this is nearly complete; only the reversibility path via restore_idea is unstated.

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 100% and both parameters are documented in the schema, so the schema does the heavy lifting. The description echoes 'reason in their own words' and implies the reason is replaceable on repeat calls, but adds no syntax, length, or id-format detail beyond the schema.

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 (decline) and resource (idea), and adds the distinguishing outcome: the idea 'leaves the planning order and is listed with declined ideas,' which separates it from delete_idea and archive_idea. It stops short of naming those siblings explicitly, so the differentiation is inferable rather than stated.

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 a clear trigger ('an idea the vibe coder decided against') and covers the repeat-call case ('declining an already declined idea replaces its reason'), but never routes the agent between this and the near-siblings delete_idea, archive_idea, or restore_idea. Usage is implied rather than prescribed.

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