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

readOnlyHint=true already tells the agent this is a safe read. The description adds genuine context beyond annotations: results are scoped to the API key owner and returned newest-first with score and status. It says nothing about pagination behavior, result caps, or what an empty result means, so it is useful but not rich.

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 front-loaded clause with zero padding: scope, ordering, and payload are all stated up front. It is a sentence fragment, which is efficient but slightly telegraphic.

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 simple two-optional-parameter read tool with annotations covering safety and a fully described schema, this is close to sufficient, and it helpfully states what fields come back even without an output schema. Minor gaps remain around pagination and result limits, which are only inferable from the schema.

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%, so limit (default 10, max 20) and domain filtering are already documented in the schema. The description adds no filtering or limit semantics of its own, so the 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?

The description names the resource (scans) and its scope (the API key owner's), plus ordering and returned fields, so an agent can tell it apart from get_scan (single scan) and list_issues. It never states the verb explicitly, relying on the name/title to convey 'list', and it does not name siblings 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?

There is no statement of when to use this versus get_scan, list_issues, or scan_site, and no prerequisites or exclusions. The only hint is the word 'recent', which implies a discovery/browse use case but leaves the agent to infer it.

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