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

The description adds significant context beyond the annotations: it explains the soft-delete mechanism ('sets `dismissed_at`'), that the row remains queryable for audit ('list_signal_inbox(include_dismissed=true)'), and that it is idempotent. It also clarifies the input is not a signal id. These details disclose the behavioral effects and constraints, going well beyond the annotation hints.

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?

The description is a tight, front-loaded sentence that covers the action, input source, effect, audit behavior, idempotence, and tier. No word is wasted; every clause earns its place.

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 single-parameter mutation tool with an output schema, the description is complete. It explains the purpose, the critical input distinction, the side effect, the audit trail behavior, idempotence, and access tier. No important context is missing.

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 coverage is 100% and the schema already describes inbox_id as 'Identifier of the inbox item to dismiss (soft-delete), as returned by list_signal_inbox.' The description adds further disambiguation with 'not a signal id', which reinforces but adds marginal value. This exceeds the baseline of 3 for high schema coverage.

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 clearly specifies the action: 'Soft-delete a single inbox item by its id', with the resource (inbox item) and the source (from list_signal_inbox). It also explicitly distinguishes from a signal id, preventing confusion with sibling tools. This is a specific verb+resource+scope.

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 provides clear context: it is for soft-deleting an inbox item, is idempotent, and is restricted to Tier sp500+. It mentions the audit use case via include_dismissed=true. However, it does not explicitly contrast with alternatives like mark_inbox_read or restore_deleted, so it lacks explicit when-not guidance.

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