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

Annotations already declare readOnlyHint, destructiveHint=false and openWorldHint=false, so the safety profile is covered and the bar is lower. The description adds content-level transparency by enumerating what the summary contains, which is useful given there is no output schema. It says nothing about data freshness, permissions, or cost, so it is solid 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 tight sentence with zero filler, and the return contents are front-loaded after the subject. It is efficient but terse to the point of being a bare list, with no verb establishing the action.

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 single-parameter read tool with full annotation coverage and no output schema, the description enumerates the returned fields well enough for an agent to know what it will get. It omits sourcing of the diagram_id and any scoping constraints, which are the only real gaps.

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?

With a single parameter at 100% schema description coverage, the schema already documents diagram_id as 'Diagram id/uuid'. The description's 'of a diagram' only restates the schema's meaning without adding format, source, or retrieval hints (e.g. where ids come from). 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 (a diagram) and the specific payload of the result: threat counts by severity, risk value, compliance and framework coverage. That is far more specific than a tautology and differentiates it from a generic summary. It does not name how it differs from near-neighbours like get_framework_coverage or compliance_status, so it stops short of a 5.

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 when-to-use or when-not-to-use guidance and no alternative tool is named. The agent must infer that this is a follow-up call after list_diagrams, purely from the singular 'a diagram' phrasing. This mirrors the MID calibration, where absent routing guidance earned a 2.

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