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

Annotations already cover the safety profile (readOnly, idempotent, openWorld, non-destructive), so the bar is lower, and the description still adds real context: results come back as binary MCP resources and the connector rejects payloads over 140,000 characters. That size cap is exactly the kind of operational constraint an agent would otherwise discover only by failing.

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?

Three short sentences, all front-loaded: purpose first, then output/limit behavior, then input requirement. No filler or redundancy.

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?

With no output schema, the description bears the burden of explaining returns, and it discloses the binary-resource result type and the size ceiling. It stops short of describing what the verification verdict itself contains (tamper/no-tamper fields), which is a minor remaining gap for a single-parameter tool.

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 coverage is 100% and the nested object already documents file_name, mime_type, download_url, content_base64 and the one-of requirement, plus the note that attachment IDs and local paths are not valid URLs. The description's 'actual file bytes or reachable URLs' restates that constraint without adding syntax or format detail, so baseline 3 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: checking an Omniseal sealed file for tampering signs. An agent can distinguish this from seal_files (creation) and retrieve/remove siblings, though the description never names an alternative directly.

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 an input precondition ('Inputs require actual file bytes or reachable URLs'), which is useful usage guidance, but never says when to reach for this tool versus the sibling seal/retrieve/remove operations or what tier of file it applies to. Usage is implied rather than stated.

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