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

With no annotations provided, the description carries the full burden. It discloses that the output is 'pure prose' and that it is 'safe to summarize,' which addresses the output format and safety profile. It does not detail potential permissions or error scenarios, but for a read-only narrative tool this is reasonable.

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?

The description is three sentences, each earning its place: purpose, usage trigger, and behavioral note. It is front-loaded and free of filler, making it easy for an agent to parse.

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 single-parameter tool with no output schema, the description is sufficiently complete: it covers what the tool does, when to use it, and what the output will be. It could arguably mention whether the narrative can be generated for all chapters or if there are rate limits, but nothing suggests a significant gap.

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%, with the single 'chapter' parameter fully documented (enum, default, format, and ct/leds distinction). The description adds no extra parameter information, so the baseline of 3 applies.

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?

The description clearly states the tool's function: providing a 'long-form narrative' for a selected chapter, including what it adds to the complexity ladder and the key teaching point. This specific verb+resource pairing distinguishes it from siblings like get_chapter_facts (facts) and run_gain_loss (numerical analysis) through the 'pure prose, no numerical claims' contrast.

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 explicitly tells when to use it: when the user asks 'walk me through this' or wants a conceptual primer. It also notes the tool is not for numerical claims, providing a when-not, but it does not name alternatives explicitly, so it falls just short of the highest score.

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