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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive), and the description goes well beyond them: it discloses the exact decision rule (hold inside 5%, blend 65% of gap under market, 50% over market), the illustrative rather than measured nature of turnover cost, and the failure mode when no median exists. That is unusually rich behavioral context.

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?

Dense and front-loaded: purpose first, then methodology, then the caveat and abort condition, with no filler. However, repeated references to 'the page's gap bands' and 'the page's illustrative' are ambiguous for an agent that cannot see the calling context.

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 advisor with no output schema, the description explains what is computed (market rent, recommended rent, turnover cost) and the abort condition, which is close to complete. It stops short of describing the returned fields explicitly and says nothing about how bedrooms/property_type affect the recommendation.

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 carry parameter meaning. It does explain zip (drives the market rent lookup) and current_rent (basis for the 1-2 month turnover cost), but bedrooms and property_type are left completely undefined in both schema and prose.

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+resource ('Lease renewal advisor') and immediately defines its scope: it computes a recommended renewal rent from a ZIP-level market estimate. That is unmistakably distinct from the calculate_* and lookup_* siblings, and it even signals its dependency on estimate_rent.

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?

Usage is implied by 'Lease renewal advisor' and by the stated abort condition ('if the rent estimate has no median, this tool stops'), but there is no explicit when-to-use-vs-alternatives guidance against siblings like estimate_rent or calculate_cash_flow. The agent must infer the scenario from the name and methodology.

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