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

Annotations already provide readOnlyHint and openWorldHint. The description adds meaningful methodology context: rental comparisons include common expenses, the gap is conservative, and results are supported by comparables/advertisers with caveats. No contradiction with annotations.

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 dense but efficient: every sentence contributes methodology, scope, or a caveat. The first sentence is long and packed with details, but no filler is present and the core concept is front-loaded.

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 12 optional parameters and no output schema, the description covers the main return fields (gap %, conservative gap, comparable counts, evidence level, cautions) and the rental/sale convention. It does not explain how pagination, sorting, evidence, or confidence filters alter results, leaving an agent to infer some behavior from enum names alone.

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 only 33%, so the description should compensate for the 8 undocumented parameters such as sort, signal, evidence, confidence, and neighborhood. It does not; the only parameter-related clarification (rent + common expenses) repeats what maxPrice already documents.

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 defines the resource: homes listed below comparable asking prices, with gap metrics and evidence levels. It lacks an explicit action verb like 'find' or 'list' and does not name sibling tools, but the intent is unmistakable and the 'no es una tasación' line adds useful scope.

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 use when searching for underpriced listings and explicitly excludes use as an appraisal ('no una tasación'). However, it does not state when to prefer this over related siblings like estimate_fair_rent or rental_market_stats, nor does it give concrete alternatives.

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