diff_analysis

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

readOnlyHint=true already tells the agent this is a safe read, so the description's job is to add context — and it does, framing the tool as a QA check that surfaces added/removed/modified deltas and states the ordering prerequisite (must follow snapshot_analysis and a change). It does not describe output format or failure modes, but the output schema covers returns.

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?

Two short paragraphs, front-loaded with the core action and followed by the when-to-use condition. The "QA reviewer" line is mildly flourishy but reinforces intent rather than wasting space.

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?

With annotations covering the safety profile and an output schema explaining the delta result, the description needs only to say what is compared and when. It covers both, though it could note what the diff does when no changes occurred.

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 100%, so both parameters (analysis_id, snapshot_id) are already documented, including that snapshot_id comes from a prior snapshot_analysis call. The description adds no syntax, format, or matching semantics beyond the schema, so baseline 3 applies.

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?

States a specific verb (compare) and resource (current analysis state vs a previous snapshot), and implicitly distinguishes itself from snapshot_analysis by referencing the snapshot it consumes. An agent can tell what this tool returns without opening the schema.

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?

"Use AFTER making changes to see what was added, removed, or modified" gives a clear temporal trigger and intent. It does not name an explicit alternative or a when-not-to-use case, so it falls just short of 5.

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