lean_diagnostic_messages

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

Annotations already declare readOnlyHint=true and idempotentHint=true, so the agent knows it's a safe, idempotent read operation. The description adds no additional behavioral context beyond stating it gets diagnostics. It is consistent with annotations.

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?

Single sentence, clear and front-loaded with the core purpose. No unnecessary words. Efficiently conveys the tool's function.

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 tool's 6 parameters, 1 required, and presence of output schema, the minimal description stating the purpose is sufficient. It could mention the output format (list of diagnostics) but the output schema covers that. Lacks nothing critical for basic understanding.

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 description coverage is 100%, so the schema already documents all parameters. The description itself does not add semantic value beyond the verb 'Get'. Baseline 3 is appropriate since the schema carries the parameter information.

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 clearly states 'Get compiler diagnostics (errors, warnings, infos) for a Lean file.' This specifies the verb (get), resource (compiler diagnostics), and scope (Lean file). It distinguishes from sibling tools like lean_code_actions (which handles actionable suggestions) but could be more explicit.

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 provides no guidance on when to use this tool versus alternatives. It does not mention conditions, prerequisites, or exclusions. Relevant usage hints (e.g., preferring lean_code_actions for 'Try This' suggestions) appear only in the parameter schema, not in the description.

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