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

Annotations already cover the safety profile (readOnlyHint=true, destructiveHint=false, openWorldHint=false), so the bar is lower. The description adds genuinely new behavioral context: results come from a SQL filter with no semantic ranking, ordering is rating- or price-based, and the return format is Schema.org Accommodation — useful given there is no output schema.

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?

Three tight sentences, front-loaded with the primary usage constraint before the alternative-tool routing. Every sentence carries routing or return-format information; nothing is redundant.

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 15-param, zero-required filter tool with no output schema, the description supplies the missing return format (Schema.org Accommodation), the ranking behavior, and the decisive routing rule versus its sibling. An agent has everything needed to select and call it correctly.

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 the schema already documents all 15 parameters, including the notable 'exact bedrooms, not minimum' semantics. The description adds no parameter-level syntax or format guidance beyond what the schema provides, so the 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 (search) and resource (rentals) plus the mechanism: SQL filter without semantic ranking, returning Schema.org Accommodation. It explicitly distinguishes itself from the sibling search_rentals_natural, so an agent can route without opening either 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?

Gives an explicit when-to-use rule ('ONLY when the query consists entirely of explicit numeric/categorical constraints with NO descriptive language') and an explicit when-not rule with named alternative ('For ANY query containing descriptors like cozy, quiet... use search_rentals_natural instead'). It even lists example descriptor words, removing inference.

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