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

With no annotations, the description carries the full burden and does disclose the read scope: public-only data, exact-target matching, and exclusion of private connected-site evidence. It says nothing about ordering, pagination, time coverage of the history, or whether repeated scans overwrite anything, which leaves meaningful behavioral gaps.

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?

A single tight sentence with the scope constraint front-loaded; nothing is wasted and the key differentiator appears before any incidental detail.

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 two-parameter read tool with no output schema and no annotations, the description covers purpose and scope adequately but omits what 'history' returns structurally and what 'limit' controls. It is callable but not fully specified.

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 0%, so the description must compensate, but it only implies the 'domain' parameter ('for a domain') and says nothing about 'limit' (max 100) or the domain string format/length constraints. The description adds minimal meaning beyond the bare schema.

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 gives a specific verb ('Retrieve') and resource ('public, exact-target scan history and observed changes for a domain'), and the scope qualifier ('public, exact-target') distinguishes it from the private-evidence sibling family. It does not name which sibling to use instead, so it falls short of full sibling differentiation.

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?

Usage is only implied: the agent can infer it is for looking up past scans of a given domain, and the clause 'excludes private connected-site evidence' acts as a partial when-not constraint. There is no explicit guidance on when to prefer this over compare_public_machine_web_evidence or scan_ai_web_readiness.

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