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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description adds genuinely useful scoping behavior: only the FIRST fix and verification step is returned, and the tool is not a findings source or a pass/fail oracle. It stops short of describing output format or how the explanation is structured, so beyond annotations it is helpful 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?

Two sentences with no filler; the positive scope leads and the exclusions follow immediately. Every clause carries information, with only minor room to fold the two exclusions into a tighter phrase.

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 read-only, single-enum-parameter tool with no output schema, the definition covers what the agent needs: valid input source, what comes back (first fix plus verification step), and what it must not be used for. Return shape remains somewhat unspecified, but that is a minor gap given the tool's narrow scope.

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 single parameter is a closed enum of eight check identifiers, which largely documents itself in the schema despite 0% description coverage. The description adds one meaningful constraint, that the value must be a supported check taken from the user's report, but gives no further per-value semantics or normalization rules.

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 ("Explain") and a tightly bounded resource ("the first fix and verification step" for a header or security.txt check). It also carves out what the tool is not (it does not retrieve report findings), which lets an agent distinguish it from report-fetching siblings without opening the schema.

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?

It states the input must be a check the user supplies from their report and adds negative guidance that the tool neither retrieves findings nor judges pass/fail. That is clear context and exclusion, though it does not name the sibling an agent should call to obtain findings or verdicts.

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