compare_scenarios

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

Annotations already provide idempotentHint=true and readOnlyHint=false. The description adds behavioral context beyond that by disclosing the optional pysd dependency and the kind of results returned. It doesn't mention side effects like CSV writing, but it does surface the dependency requirement, which is useful for the agent.

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 two sentences: the first conveys the core purpose and output in a dense, front-loaded manner; the second adds an essential prerequisite (pysd dependency) with an install command. No fluff, no repetition, and every sentence earns its place.

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?

Given the tool's complexity (7 parameters, nested objects, output schema present), the description provides a solid high-level overview of behavior and prerequisites. The schema covers parameter details, and the output schema covers return values. The optional CSV writing is not mentioned, but that is a minor gap for a tool this well-specified.

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 has 100% parameter documentation, so the baseline is 3. The description clarifies the concept of 'scenarios' as constant overrides and explains the divergence metrics, but it doesn't add per-parameter meaning beyond what the schema already provides, so no higher score is warranted.

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's action: 'Run several named what-if scenarios against a baseline and report how each diverges'. It specifies the output (per-variable final/max absolute deltas and final percent change), distinguishing it from sibling tools like simulate or sensitivity_analysis which do different kinds of analysis.

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 gives clear context on when to use this tool: for comparing multiple named what-if scenarios against a baseline. It does not explicitly name alternatives, but the scenario-comparison focus makes the intended use evident. No exclusions are mentioned, which fits a 'clear context, no exclusions' level.

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