scan_update_set_sca

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

The description declares 'Read-only', but annotations set readOnlyHint=false, a direct conflict that an agent must resolve before calling (likely explained by openWorldHint=true and the external OSV lookup, but that is never said). Setting that aside, it does add real behavioral value: hashed evidence only, source code never returned, exact-version matching. The contradiction still undermines trust in the safety profile.

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 tight, front-loaded sentences with no filler; the scope ('Read-only') and the key output constraint ('source code is never returned') both land immediately. Jargon density (SCA, hashed evidence) is high but each phrase carries information.

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 no output schema, the description still conveys the return shape (component metadata, hashed evidence, no source) and truncation behavior is covered by the schema's max_records note. What it omits is the external-dependency behavior (OSV reachability/timeouts) and any error behavior for an unknown update set name.

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 all three parameters (update_set, max_records, lookup_vulnerabilities) are already fully documented in the schema, and the description adds no parameter-level detail. Baseline 3 applies when the schema does the heavy lifting.

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 specific verb and resource ('SCA scan for an Update Set') and disambiguates the output ('normalized, exact-version component metadata with hashed evidence only'), which separates it from siblings like review_update_set_best_practices or preview_update_set. It never names a sibling explicitly, so differentiation is inferred rather than stated.

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 guidance on when to run this versus the other update-set tools (preview_update_set, review_update_set_best_practices, scan_vulnerabilities) and no stated preconditions such as needing a committed or exported set. The only conditional advice ('Set false to perform local collection only') lives in the schema, not the description.

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