Verify Outside Expectations Now

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

Adds substantial context beyond the annotations: rate limiting (a few checks per minute), the 'unknown is never a pass' outcome rule, that each tool is read once and a signed observation receipt is produced, and the 30-day retention of the anonymous set. This is well beyond what readOnlyHint/idempotentHint convey.

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 dense paragraph that front-loads the two modes and then layers outcomes, receipts, and rate limits. Every clause carries information, though the density makes it slightly taxing to parse.

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 tool with an output schema and full schema coverage, the description supplies modes, outcome semantics, retention, and rate limits. Return-format details are correctly delegated to the output schema, so nothing critical 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 100%, so the baseline is 3. The description adds real value by clarifying the mutually exclusive usage modes (id from set_expectations vs. domain+expect once, storing nothing) that the flat schema does not express.

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?

States a specific verb+resource ('check expectations from outside now') and spells out the two operating modes — stored set by id vs. one-off domain+checks. It explicitly relates itself to the sibling set_expectations, so an agent can distinguish them without opening a 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?

Gives a concrete context ('typical use: right after a change, to see whether it is visible from outside yet') and notes external DNS/CDN propagation lag. It references set_expectations as the stateful counterpart, but never states an explicit 'use set_expectations instead when…' exclusion, so the when-not is only implied.

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