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

Annotations already cover the safety profile: read-only, idempotent, non-destructive, and closed-world. The description adds useful behavioral context beyond that, including the Census source, the ten-year trend, and the connection to HUD upfront MIP and construction interest, though it does not describe exact return shape or limitations of averages.

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 definition is a single front-loaded sentence with no filler, beginning with the data source and core metrics. It is dense but efficient; splitting the HUD/interest clause into a second sentence would improve readability without changing substance.

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 three optional parameters and no output schema, the description is largely complete: it explains the data source, measured durations, dimensions, trend scope, and practical interpretation. It does not describe the response structure in detail, but it gives enough for an agent to invoke the tool 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 100%, and the schema already documents all three parameters, including defaults and the year-completion meaning. The description reinforces region, building-size categories, and the one-year-plus-trend scope, but adds little parameter semantics beyond what is already structured.

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 names a specific data source and resource: Census Survey of Construction averages for apartment buildings, with months from permit to start and start to completion. It also scopes the data by region, building size, completion year, and ten-year trend, making it clearly distinct from sibling tools about market conditions, loan sizing, or construction options.

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 the stated content: an agent can infer this is the tool for build-duration questions and HUD MIP/interest context. However, the description does not explicitly say when to use it versus the sibling tools, nor does it state any exclusions or prerequisites.

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