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

Annotations already declare readOnlyHint and idempotentHint, so the barrier is lower. The description adds useful context: the checklist is 'deterministic, sourced from the guide corpus', and explicitly states that it does not perform analysis of specific buildings or listings. This goes beyond the annotations and clarifies expected behavior.

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, front-loaded with the main action and scope. The second sentence clarifies limitations without wasting words. 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 has 6 optional parameters and no output schema, the description does enough by clearly stating the purpose, the source corpus, and non-goals. It could briefly mention the output format or how to use the buyingStage parameter, but overall the context is adequate for a checklist-generation tool.

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 schema has 67% description coverage, with era, buyingStage, jurisdiction, and propertyType already described. The tool description does not add any parameter-level meaning beyond what the schema provides. The limit and concerns parameters remain partially undocumented, but the description offers no compensation. Baseline 3 is appropriate given the high schema coverage.

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 uses a specific verb ('Build') and resource ('Homechecker guide corpus') and clearly defines the output as a checklist for a buyer context. It also distinguishes itself from sibling tools (get_guide, list_guides, search_guides) by emphasizing that it assembles a checklist rather than simply retrieving or searching guides.

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 provides a clear when-not condition ('does not analyse a listing, document or actual building'), implicitly distinguishing it from analytical or retrieval tasks. However, it does not explicitly name alternative tools or scenarios where a sibling should be used, so it falls short of full explicit guidance.

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