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

Annotations already declare readOnlyHint=true, but the description goes well beyond this by disclosing the exact payload returned (criterion, input_contract, etc.), the NotFound behavior for system/revoked/inaccessible verifiers, the config_hash for drift detection, and the access model for grantees. No contradiction with annotations; the read-only nature is consistently reinforced.

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 longer than average but every sentence earns its place: it front-loads the core purpose and scope, then methodically covers access rules, system exclusion, version defaults, and return payload. No redundancy or filler; it is an efficient, well-organized explanation.

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?

The tool is complex enough (2 params, versioning, access control, specific return fields) that the description covers all necessary aspects: what is returned, when NotFound occurs, how version pinning works, and what caller permissions are required. The presence of an output schema reduces the burden, and this description exceeds that burden by preemptively explaining the key fields.

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?

Although schema coverage is 100%, the description adds substantial semantic depth: verifier_id is explained as accepting a UUID or an accessible user-scope name, and version is described as defaulting to the latest with explicit behavior when pinned. This goes far beyond the schema's terse descriptions and materially helps the agent pick and fill parameters correctly.

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 opens with a precise verb and resource ('Read a verifier's full definition') and immediately scopes it ('user-scoped verifiers only'), distinguishing it from run_verifier and list_verifiers. It also specifies what is excluded (platform/system verifiers), making its purpose unmistakable among siblings.

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?

While it does not explicitly name 'use list_verifiers instead for listing', it provides clear when-to-use context: reading a specific verifier's full definition, with explicit exclusions (system verifiers never returned) and access rules (owner and grantees can read). The version pinning guidance and the behavior for inaccessible/revoked verifiers further clarify when this tool is appropriate.

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