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

Beyond the annotations (readOnlyHint, idempotentHint, destructiveHint), the description adds concrete behavioral details: 'writes no files and uses no network' and 'has no project inputs'. This provides valuable context not captured in the annotations alone.

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 compact yet information-dense. Each sentence serves a purpose: what it does, when to use it, what the inputs are, and what the effects are. No wasted words.

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?

The tool is simple (one optional parameter) and has an output schema. The description covers the purpose, usage timing, alternatives, input semantics, and effects, making it complete for an agent to select and invoke correctly.

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 has 100% coverage with a clear enum description. The description adds meaning by stating 'format changes rendering only' and clarifying the smoke test has no project inputs, reinforcing that format is the only parameter and only affects output presentation.

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 it runs a source-free compiler smoke test through the real Axint pipeline, using a specific verb and resource. It distinguishes itself from siblings by explicitly mentioning 'use validate or run for project checks'.

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?

Explicitly says to call immediately after install or first MCP connection, and that validate or run should be used for project checks. This gives concrete when-to-use guidance and names alternatives.

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