trace_matrix

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 behavioral content by naming the two unexpected payload categories (unrequested code and annotations naming unknown requirements), which tells the agent to expect edge-case rows. It stops short of saying whether the matrix is full-system or scoped, which matters for a tool with no filter parameters.

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 dense sentence with the primary deliverable front-loaded and the edge-case content trailing. No filler, though the arrow chain and the 'plus' clause make it slightly harder to parse than a plain statement.

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 an output schema present and zero parameters, the description need not document return fields; it correctly spends its words on scope instead. It is complete enough to call, but a reader cannot tell how this differs from the sibling reporting tools, which is the one remaining gap.

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 tool takes zero parameters, so there is nothing for the description to disambiguate; baseline 4 applies. No parameter claims are made that could mislead.

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 concrete deliverable: a full traceability matrix spanning requirement -> code -> tests -> latest results, plus orphan code and annotations referencing unknown requirements. That is a specific resource and scope, not a tautology. It does not, however, distinguish itself from siblings like coverage_report, evidence_report, or find_gaps, which on their face produce overlapping views.

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 sibling is named. An agent must infer from the content that this is the broad end-to-end traceability view rather than a filtered report, which is exactly the decision it needs help with among eleven siblings.

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