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

The annotations indicate readOnlyHint=false, so the tool modifies state, but the description does not elaborate on side effects (e.g., whether it marks the session as ended, whether calling it multiple times has different effects, or what happens if the session is already ended). The description does mention it returns a summary, which is helpful, but it leaves some behavioral details implicit.

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 concise and well-structured. It uses two short sentences to convey the action, the output, and the expected user-facing summary. No redundant or vague wording is present.

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?

Given the sibling tools (start_study_session, submit_review, etc.), the description provides sufficient context for an agent to understand the tool's role in the study session workflow. It could be more explicit about session state requirements, but the overall context is adequate.

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?

The schema provides only a required integer session_id with no description (coverage 0%). The tool description does not elaborate on what session_id refers to, though the tool's purpose makes it reasonably inferable. The description adds no extra clarity beyond the parameter name and the tool's function.

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 purpose: to end a study session and retrieve its summary. It also specifies the output format (counts by rating and total reviewed) and instructs the agent to give a one-sentence recap, making the intent unambiguous.

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 explains what the tool does but does not explicitly state when to use it relative to sibling tools (e.g., after completing all reviews, or to close an active session). It lacks guidance on preconditions or alternatives, though the tool name and context imply it should be used after start_study_session.

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