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

Annotations only supply a safety profile (readOnlyHint=false, destructiveHint=false, openWorldHint=false), so the description carries the burden of describing effect and does add real context: blocking affects future discovery of the entire domain, and blocking requires a reason. It omits reversibility (an unblock tool exists) and any permission requirements.

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?

A single front-loaded sentence covering both operating modes and the one hard constraint, with zero filler. Nothing could be removed without losing meaning.

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 mutation tool with annotations covering the safety profile and no output schema to explain, the description covers both branches of the operation and the reason requirement. Gaps remain around reversibility of the domain block and whether the prospect record is retained, but nothing essential to invoking the tool correctly is 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?

Schema description coverage is 0%, and the description only illuminates the 'decision' parameter (reject vs block, reason required for block) — which largely restates the schema's oneOf required fields. projectId, siteId, and prospectId receive no explanation of what they identify or how to obtain them.

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 and resource ('reject one prospect') plus a second mode ('block its whole domain from future discovery'), so the dual behavior of the tool is evident. It does not explicitly name or contrast with the sibling that reverses the block (unblock_prospect_domain), so it stops short of full sibling differentiation.

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 a conditional hint ('a reason is required to block'), which tells the agent which branch needs what, but there is no explicit guidance on when to reject a single prospect versus blocking the whole domain, and no named alternatives. Usage is implied rather than prescribed.

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