read_lesson

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

With no annotations, the description carries full burden. It explicitly states the tool is read-only ('只读 advisory 内容'), details the return fields, explains error behavior for missing ids, and mentions the apply_response_cap transformation. No side effects are hidden, and the read-only nature is clear.

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 well-structured with labeled sections (purpose, trigger, parameter, return) and front-loads the main action. It is slightly longer than strictly necessary, but every sentence adds useful detail, and the formatting aids scanning.

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?

With no output schema, the description explains the full return shape and error code. It covers usage context, alternatives, parameter source, and behavioral constraints. For a simple read tool with one parameter, this is complete.

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 provides zero description coverage, so the description must fully explain the 'id' parameter. It gives a concrete format example and instructs that the id comes from search_lessons. This completely compensates for the schema gap.

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 opens with a specific verb+resource: '按 id 拉取单条 lesson 的完整 markdown 全文' (fetch complete markdown by id). It explicitly distinguishes this from search_lessons (which finds lessons) and from other advisory tools, making its scope clear and unique among siblings.

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?

It states when to use: 'search_lessons 命中后按需拉全文' (after search_lessons hits, fetch as needed) and notes drafts are readable. It also names what it does NOT replace (verify_hou_api, get_houdini_help, get_best_practices) and cautions against replacing live verification. This is explicit when/when-not guidance.

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