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

Annotations declare readOnlyHint=false, destructiveHint=false and idempotentHint=false, so the safety profile is largely covered. The description adds genuine extra context the annotations lack: the dismissal is persistent ('for good' — later scans keep the choice) and is reversible via undo, which is the key behavior an agent needs.

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 short, front-loaded sentences with zero filler. The persistence trait comes first and the reversal path second, which is the right ordering for an agent deciding whether to call it.

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 four-parameter mutation with full schema coverage, no output schema and annotations covering safety, the description covers what the tool does and its persistence/reversal semantics. It omits the confirm-guard interaction, but that parameter is fully explained in the schema, so the gap is minor.

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 four parameters (root, undo, app_id, confirm) are already documented in the schema. The description restates the undo semantics ('puts a dismissed suggestion back on the rail') but adds no syntax or format detail beyond what the schema provides, matching the baseline 3.

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 verb and resource ('Hide a suggestion for good'), making the mutation unambiguous. It implicitly distinguishes itself from the read-side siblings like get_competitor_suggestions, but never names an alternative, 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?

The description explains the undo branch ('undo: true puts a dismissed suggestion back on the rail'), which tells the agent when to use that mode. However, it gives no guidance on when to prefer dismiss vs. add_suggested_competitor or get_competitor_suggestions, leaving the primary usage context implied.

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