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

With no annotations, the description carries the full burden and does so well: it discloses that the call is free, unauthenticated, and requires no account, and it defines what VERIFIED technically means (Ed25519 signature recomputes against apir.ai's published key, unexpired, unrevoked) versus what it does not guarantee (good behavior). The explicit warning against over-reading VERIFIED and NO_RECORD is exactly the kind of interpretation context annotations could never supply.

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?

Front-loaded with the verb and resource, then the accepted inputs, then the verdict set, then the interpretation caveats. Every sentence adds decision-relevant information (verdict semantics, over-reading warning, cost/auth facts); nothing is padding.

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?

No output schema exists, so the description takes on the job of documenting all seven possible verdicts and their meanings, which it does explicitly, including the counterintuitive NO_RECORD case. Combined with the auth/cost disclosure that substitutes for missing annotations, nothing an agent needs to call or interpret this tool is absent.

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 single 'query' parameter is already documented with the same accepted forms (agent name, credential id, UUID, domain, DID). The description restates that list without adding syntax, matching, or disambiguation rules, so the baseline 3 for a fully-documented schema applies.

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 and resource ('check whether an AI agent carries a real, cryptographically signed credential') and enumerates the five accepted identifier forms. The scope is narrow enough that an agent can distinguish it from get_verification_keys (which supplies keys) and check_authority (which is about authority) without opening any 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 clear context for when this tool applies (any claim an agent makes about itself needs verification) and explicitly frames NO_RECORD as an honest answer rather than a red flag. It does not name the sibling tools or state when not to use this one, so the routing guidance is strong but not complete.

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