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

Annotations already establish this is a safe, read-only, idempotent, closed-world read, so the description spends its words on what annotations cannot convey: data provenance (Altus Group averages, public REIT 10-Q disclosures), the specific quarter, the quoting convention (spreads over 5-/10-year Treasury or Term SOFR, by LTV band), and the presence of the current benchmark rate. That is exactly the extra context an agent needs to trust and interpret the numbers.

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?

It leads with the purpose and every clause carries substantive information about contents or sourcing rather than filler. The single elaborate sentence is somewhat run-on and could be split for scanability, which keeps it below a 5.

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 no output schema, the description carries the burden of describing what comes back, and it does: fixed and floating lender quotes by LTV band, the current 10-year Treasury, implied all-in senior and mezzanine rates, and REIT-reported earnings per layer. An agent knows what it will receive and for which period.

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 single `layer` enum is fully described in the schema, so the description's 'Filter by layer' adds no meaning beyond it. Baseline 3 applies when the schema does all the parameter work.

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 the exact resource and scope: cost of senior debt, mezzanine and preferred equity, sourced from Altus Group Q2 2026 quotes and REIT 10-Qs. It is unmistakably a pricing/cost tool, which implicitly separates it from `capital_stack` (structure) and `list_capital_providers` (providers), but it never names those siblings to make the distinction explicit.

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 only usage instruction is the closing 'Filter by layer,' which restates the parameter rather than guiding tool selection. There is no statement of when to reach for this versus `capital_stack` or `list_capital_providers`, and no prerequisites or exclusions.

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