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

No annotations are supplied, so the description must carry the full disclosure burden, and it does disclose a non-obvious behavioral trait: engine errors reference a rule name rather than the underlying mistake, which is why lookup beats inference. The word 'explain' implies a non-mutating operation and the round-trip remark hints at cost. What is missing is explicit confirmation that the tool is read-only, and what happens with unrecognized messages; the presence of an output schema removes the need to describe return shape.

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 sentences, zero waste, and the core purpose is front-loaded before the input constraint and the usage justification. Every clause carries information an agent would otherwise have to guess.

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?

For a single-parameter tool with an output schema, the description is nearly sufficient: purpose, input handling, and timing are all covered. The remaining gap is scope, since it does not say how the tool behaves if the pasted text is not a manifoldbt error, leaving the failure mode undefined.

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 documents the single required 'message' string with 0% description coverage, so the description must compensate, and 'Paste the message verbatim' does add real meaning: it tells the agent not to paraphrase, summarize, or extract a fragment. It does not specify whether surrounding stack context is acceptable or how long a message may be.

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?

Names a specific verb (explain) and a specific resource (an error returned by the manifoldbt engine), then enumerates the three things it returns: meaning, cause, and fix. This is clearly distinct from siblings like search_docs and get_capabilities, which retrieve material rather than interpret a specific message.

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 explicit when-to-use guidance: call this before changing code in response to an engine error, with a concrete rationale (messages name a rule, not the mistake; guessing wastes a round trip). It also gives an input precondition, 'paste the message verbatim.' It stops short of naming alternatives or stating when not to use it (e.g. for errors not produced by the engine).

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