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

Beyond the readOnlyHint annotation, the description adds valuable behavioral context: 'computed deterministically (no AI, no tokens)' assures the user of zero cost and predictable output. It also details the return categories, which enriches the user's mental model.

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 well-structured: it opens with the core idea, enumerates the three kinds, and ends with usage guidance. Every sentence contributes meaningful information without redundancy, and it remains readable despite its length.

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 read-only tool with no output schema, the description adequately explains what the tool returns by naming the three kinds of drift. It lacks a precise output format (e.g., list of objects with fields), but the enumeration is sufficient for an agent to understand the tool's value and integration.

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 one required-less parameter 'project_id' with 0% description coverage, and the description does not mention it at all. While the parameter is self-explanatory, the description fails to compensate for the low schema coverage, leaving the parameter's role implicit.

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 identifies the tool as returning a list of drift between the Idea lane and System Specs. It specifies three distinct kinds of stale items, making the purpose concrete and distinguishing it from sibling tools like report_drift or resync_from_idea.

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?

It explicitly says 'Read this before assuming the design is coherent', giving a clear precondition for use. It also directs the user to resync_from_idea for fixing the first kind, naming an alternative tool and its purpose.

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