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

Annotations already declare readOnlyHint=true and idempotentHint=true, covering the safety profile. The description adds value beyond annotations by noting that each result has a URL on a-du.homes where a free test fit is offered, and that pre-approved cities shorten plan check. These are useful behavioral/contextual details not present in the schema or annotations. No contradiction detected.

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 moderately long but every sentence earns its place: purpose, usage examples, result URL note, and a concrete example. It is front-loaded with the core purpose, and the example at the end is a helpful reference. No redundant filler.

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 search tool with no output schema, it lists the result attributes (size, bedrooms, plan price, etc.) and mentions the URL on a-du.homes. It covers filtering guidance and an example. Pagination and cursor are handled by the schema, so the description is sufficient for an agent to 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 coverage is only 57%, leaving max_sqft, min_sqft, and bedrooms_min without descriptions. The description compensates by listing these attributes ('size, bedrooms') and provides an explicit example: {"bedrooms_min": 1, "max_sqft": 800, "pre_approved_in": "Los Angeles"}. It also clarifies max_plan_price via 'plan price' and pre_approved_in via city filtering, adding meaning beyond the schema.

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 opens with a specific verb and resource: 'Search A-du Build, the marketplace of ADU plan sets'. It lists the searchable attributes (size, bedrooms, plan price, etc.) and gives example intents. This clearly distinguishes it from generic sibling tools like 'search' or 'search_rentals' by targeting ADU plans specifically.

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?

It explicitly states when to use the tool with three concrete example user queries: 'find me an ADU plan', 'how much does a plan cost', 'what pre-approved plans exist for <city>'. It also advises filtering by pre_approved_in. However, it does not mention when not to use it or point to alternatives like match_plans_to_lot, so it lacks the 'when-not' and 'alternatives' components.

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