Set the spoiler limit

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

Annotations already indicate mutation (readOnlyHint=false) and possible outside effects (openWorldHint=true). The description adds specific behavioral detail beyond that: chapters, episodes, and arcs past the limit are withheld, and article sections about later arcs are removed. It also discloses the off-switch behavior, enriching the agent's mental model.

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 sentences with each earning its place: main action, consequence/side effect, and usage trigger with examples. No filler or repetition. The structure front-loads the most important information.

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 2-parameter tool with no output schema, annotations covering idempotency/open-world, and a sibling getter, the description is complete. It covers purpose, side effects, when to invoke, and how to disable. The schema itself documents each parameter, so no critical information is missing.

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 baseline is 3. The description adds value by explaining the no-chapter-to-turn-off behavior and giving an arc example that shows how the parameter maps to a chapter cutoff. This goes beyond the schema's field-level descriptions and clarifies real usage.

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?

Description opens with a specific verb and resource: 'Set the last manga chapter the user has read.' It goes beyond a bare statement by explaining the consequence (chapters/episodes/arcs past it are withheld) and clearly distinguishes itself from the sibling get_spoiler_limit, which reads rather than sets.

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 description gives an explicit usage trigger: 'Use this whenever the user says how far they are' with concrete examples (chapter 900, Enies Lobby). It also explains how to turn the limit off. It does not mention alternatives or exclusions, but no alternative setter exists among siblings, so the guidance is clear and actionable.

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