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

Annotations already declare readOnlyHint=true, destructiveHint=false, and idempotentHint=true, so the safety profile is clear. The description adds that node IDs must come from introspection_system_list_nodes, which is useful prerequisite context, but it does not elaborate on error behavior, edge cases, or the exact nature of the structural difference returned.

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 mostly concise, leading with the purpose and then parameter hints. However, the example 'call introspection_system_diff with arguments {}' is misleading because the tool requires four arguments, and the example provides no illustrative value. This detracts from clarity.

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 comparison tool with no output schema, the description covers the essential context: what it does, what it returns (structural difference), and where valid node IDs come from. It does not define the exact structure of the diff, but that may be acceptable given the tool's simplicity and the presence of related introspection tools.

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 0%, so the description must compensate. It explains baseline_kind as a constant 'since', provides the ISO date format, and references node_kind/node_id from the confidence tool. This adds meaning beyond the schema's constraints, though it does not explicitly describe all parameter purposes or the meaning of the return structure.

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 states a specific action (compare) on a specific resource (node's evidence) against a baseline date, clearly distinguishing it from sibling introspection tools like confidence. It also specifies the return type, making the purpose 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 implies usage (comparing evidence to a baseline) and references a sibling tool ('same as confidence') for parameter context, but does not explicitly state when to use this over alternatives like introspection_system_change_graph or when not to use it. The mention of valid node IDs from list_nodes provides prerequisite guidance.

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