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

Annotations already cover the safety profile (readOnlyHint=true, idempotent, non-destructive), and the description adds genuinely useful context beyond that: the exact cost model ($1.00 rubric fee + advertised per-call price x 10 probe calls), the fact that the quote itself is free while the re-test is paid, and the directory-membership prerequisite.

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?

Four compact sentences, front-loaded with purpose and cost before the payment path and prerequisite. Every sentence adds information (what, price, next step, precondition) with no 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?

Output schema exists so return values need not be explained, yet the description still tells the agent what the total consists of. Purpose, cost, next action, and name-resolution prerequisite are all present, leaving nothing an agent needs missing.

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?

With 100% schema description coverage, the baseline is 3. The description goes slightly beyond the schema by specifying that service_name must exist in the directory and must be the exact name obtained from search_services, adding a validity constraint not spelled out in 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 uses a specific verb+resource ('Get an upfront quote ... to re-test a service we have already reviewed') and immediately scopes it to a reviewed service, which distinguishes it from request_review and get_review. An agent can tell what it does and what it does not do without opening the schema.

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 gives concrete triggering conditions (quality changed, review stale, measured numbers no longer match) and explicitly names the alternatives: search_services to find the exact name and accept_retest_quote to proceed after payment. When-to-use, prerequisites, and the next step are all stated.

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