Validate Completion Evidence

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

Annotations already indicate readOnlyHint=true and openWorldHint=false. The description adds behavioral context: pre-validation against schemas and forbidden fields, and that it is not authoritative (Harbor is authoritative at submit time). This provides useful transparency beyond the annotations, though it could detail the validation result behavior.

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 two sentences, front-loaded with the core purpose in the first sentence. Every word adds value: the first sentence defines the action and scope, the second gives usage condition and caveat. No redundant or irrelevant content.

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?

Given the presence of an output schema (though not provided in the input), the description need not detail return values. It adequately covers the tool's purpose, prerequisite, and non-authoritative nature. However, it could mention what 'catalog JSON Schemas' refers to or hint at the validation outcome format, making it slightly less complete.

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?

The description does not explain any of the 6 parameters beyond mentioning 'vendor and canonical completion evidence', which loosely maps to vendor_payload and canonical_payload. The frozen_* parameters and preset_id are not described at all. Since schema description coverage is 0%, the description should compensate but fails to add meaningful parameter semantics.

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's function: pre-validating vendor and canonical completion evidence against JSON schemas and forbidden fields. It distinguishes itself from sibling submit tools (e.g., paybond_submit_evidence) by explicitly stating it's a pre-validation step, and notes that Harbor is authoritative at submit time, clarifying its role.

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 explicitly states when this tool is required: before evidence submit tools when PAYBOND_MCP_EVIDENCE_POLICY=strict. While it provides clear context for use, it does not explicitly mention when not to use it or name alternative tools for other scenarios, which prevents a score of 5.

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