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

Annotations already carry destructiveHint=true, so the destructive nature is known. The description adds value beyond annotations by disclosing role restrictions (buyer-only, principal) and the specific workflow state that triggers the second use case. It stops short of describing side effects or finality, but with the annotation covering destructiveness, this is adequate.

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?

Two compact sentences with no wasted words. The primary use case is front-loaded, and the secondary principal use case is appended as a clearly marked additional context. 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?

For a low-complexity tool with one parameter and no output schema, the description covers the key decision factors: who can call it, what state the quote must be in, and the cap-kickback scenario. It does not describe post-rejection behavior or side effects, but destructiveHint already signals the outcome profile. Minor gap, not a significant one.

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 100%, and the schema already documents service_quote_id as 'UUID of the quote thread to reject.' The description adds no additional parameter-level detail, such as how to obtain the ID or what distinguishes a quote thread from other IDs. Baseline 3 applies because the schema does the heavy lifting.

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 ('Reject') with a precise resource ('a submitted quote') and adds caller restrictions ('buyer-only'). The second sentence adds a distinct secondary use case (principal denying a quote in pending_principal_confirmation after a cap kickback). This clearly differentiates it from siblings like services_accept_quote, services_counter_quote, and services_withdraw_quote.

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 gives clear contextual conditions for both invocation scenarios: a buyer rejecting a submitted quote, and a principal denying a quote in pending_principal_confirmation after a cap kickback. It does not explicitly name alternatives or state when not to use this tool, but the state-based guidance is specific enough for an agent to route correctly.

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