trw_surface_diff

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

Despite lacking annotations, the description discloses the diff logic by explaining that 'changed' entries appear in both snapshots with different content_hash values, and it lists the output fields. This provides clear behavioral transparency about the comparison criterion and result structure.

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 highly concise at two sentences: the first states the overall purpose and the second details the output format. Every word earns its place with no redundancy, and the key information is front-loaded.

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 tool with two parameters and no output schema, the description adequately explains core functionality and output structure. However, it omits context such as error behavior when snapshots are missing or prerequisites for the input IDs, which would improve completeness.

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 input schema includes two required string parameters (snapshot_id_a, snapshot_id_b) with no descriptions, and the tool description adds no clarification about them. Schema coverage is 0%, so the description should compensate but does not, leaving parameter semantics largely 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 states the tool performs a 'structured diff between two surface snapshots' and specifies the return format with 'added, removed, changed' lists of surface_id strings. The purpose is specific and actionable, though it does not explicitly differentiate from sibling tools like trw_surface_classify.

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?

No guidance is provided on when to use this tool versus alternatives, nor are there any prerequisites or exclusions mentioned. The description is purely functional without contextual usage advice.

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