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

Annotations already indicate a read-only, idempotent, non-destructive operation. The description adds valuable behavioral context: no API key is needed, the result is hash-verifiable, and the content is identical to the standard agent.json. No contradiction with annotations.

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 compact and front-loads the most actionable fact: no API key is needed. The imperative 'call this now' and the emoji add minor noise, but the substantive content is focused and well organized.

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 zero-parameter, read-only retrieval tool with an output schema and strong annotations, the description is complete: it identifies what is returned, provides provenance, and explains how to use the result before acting. Nothing essential is missing for correct invocation.

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?

There are zero parameters, so the baseline is 4. The schema already states 'No arguments' and explains that the owner is derived from the authenticated principal, so the description does not need to add parameter-level detail.

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 clearly states the tool fetches the AgentContractV1 descriptor (version, schema_url, schema_hash) and hosted_runtime facts, and it adds the useful equivalence to /.well-known/agent.json. However, it does not explicitly distinguish this from the sibling verify_contract, and the validation instruction slightly blurs the retrieval boundary.

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 implies when to use the tool through 'call this now' and 'before acting', suggesting it is a preliminary, low-friction step. It does not name alternatives or state when not to use it, leaving the choice between this and verify_contract to inference.

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