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

Beyond the annotations (readOnly, openWorld, idempotent), the description adds crucial context: no persistence, incomplete fee schedules, the meaning of pricing_coverage='partial_estimate', and a mandatory disclosure ('Always relay pricing_disclosure'). This fully informs the agent of behavioral expectations.

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 relatively dense but each sentence earns its place: scope, persistence, fee caveat, estimate handling, and disclosure. It is longer than minimal, but the added details are necessary given the tool's complexity.

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 explains key response fields (included_in_price, pricing_coverage, excluded, pricing_disclosure) and provides safety caveats. It adequately covers what the tool returns and how to interpret it, making it complete for an AI agent.

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 0%, so the description must compensate. It clearly explains 'rooftop_slug' by saying 'at a named rooftop (pass rooftop_slug)', but the 'identity' parameter is left unexplained. Partial compensation results in a middling score.

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 states a specific verb ('preview') and resource ('out-the-door price') with clear scoping ('one available unit at a named rooftop'). It distinguishes itself from likely sibling deal_quote by emphasizing read-only preview, making its purpose unambiguous.

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 provides clear context: 'free to call while browsing' and 'Persists nothing' signal when it is appropriate to use. However, it does not explicitly contrast with alternative tools like deal_quote, so it isn't a full 5.

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