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

Annotations already declare readOnlyHint, idempotentHint, closed-world and non-destructive, so the safety profile is covered. The description adds the valuable detail that a returned course carries favorite/like flags and that stats are opt-in via withStats, which is beyond what structured fields say. It omits what happens when the course does not exist, which is the main remaining behavioral gap.

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 short sentences, front-loaded with what the tool returns, then the flag nuance, then the alternative. No filler and nothing repeated from the title.

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 correctly compensates by naming the fields returned, and annotations carry the safety profile for a two-parameter read tool. Not found / error behavior for an invalid courseId is the one thing an agent might still need.

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 only 50%, and the undocumented parameter (withStats) is the one the description explains in plain language: it adds counts of documents per type. courseId is covered by the schema as required and length-bounded. Missing only a statement that withStats defaults to off.

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 and resource ('Open one course') and enumerates the fields it returns (name, code, school, favorite/like flags). It also explicitly names list_course_documents as the tool for documents, so an agent can separate the two without opening a schema. Slightly short of 5 only because the 'Open' verb is loose next to the many get_* 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?

Gives a clear routing rule ('Use list_course_documents for its documents') and explains the conditional flag ('withStats=true adds...'). No explicit exclusions or mention of when a course id is unknown/invalid, but the context for use is unambiguous.

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