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

Annotations already indicate read-only and non-destructive behavior. The description adds valuable disclosure that outputs are illustrative, not observed income, forecasts, guarantees, or advice. Also clarifies no external data is used, which goes beyond annotation hints.

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 sentences, front-loaded with function then limitations. No redundant information. Every sentence contributes to understanding the tool's scope and caveats.

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?

The description, combined with the output schema and annotations, provides a complete picture. It covers inputs, computation scope, exclusions, and important disclaimers. The presence of an output schema means return value documentation is handled externally.

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 covers 80% of parameters with descriptions. The description mentions the four key inputs but does not add per-parameter semantics beyond what schema already provides. It also omits the optional city parameter. Baseline 3 is appropriate.

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 calculates an illustrative long-term-rent scenario using specific caller-supplied inputs. It distinguishes itself from market-data tools by explicitly stating no market baseline or occupancy assumption is used.

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 when to use this tool: when the user has their own assumptions and wants an illustrative calculation. It explicitly excludes market baselines and occupancy assumptions, which signals not to use it for market-based estimates. However, it does not name alternative sibling tools explicitly, so it falls short of a 5.

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